diff --git a/src/libslic3r/GCode.cpp b/src/libslic3r/GCode.cpp
index e3624e8bd9..5e8e5e5774 100644
--- a/src/libslic3r/GCode.cpp
+++ b/src/libslic3r/GCode.cpp
@@ -2446,7 +2446,7 @@ void GCode::_do_export(Print& print, GCodeOutputStream &file, ThumbnailsGenerato
     //resize
     first_non_support_filaments.resize(print.config().nozzle_diameter.size(), -1);
     first_filaments.resize(print.config().nozzle_diameter.size(), -1);
-
+    float max_additional_fan = 0.f;
     if (print.config().print_sequence == PrintSequence::ByObject) {
         // Order object instances for sequential print.
         print_object_instances_ordering = sort_object_instances_by_model_order(print);
@@ -2459,6 +2459,9 @@ void GCode::_do_export(Print& print, GCodeOutputStream &file, ThumbnailsGenerato
             tool_ordering = ToolOrdering(*(*print_object_instance_sequential_active)->print_object, initial_extruder_id);
 
             tool_ordering.sort_and_build_data(*(*print_object_instance_sequential_active)->print_object,initial_extruder_id);
+            float temp_max_additional_fan = tool_ordering.cal_max_additional_fan(print.config());
+            if(temp_max_additional_fan > max_additional_fan )
+                        max_additional_fan = temp_max_additional_fan;
             if (!find_fist_non_support_filament && tool_ordering.first_extruder() != (unsigned int) -1) {
                 //BBS: try to find the non-support filament extruder if is multi color and initial_extruder is support filament
                 if (initial_extruder_id == (unsigned int) -1) {
@@ -2482,6 +2485,9 @@ void GCode::_do_export(Print& print, GCodeOutputStream &file, ThumbnailsGenerato
         // If the tool ordering has been pre-calculated by Print class for wipe tower already, reuse it.
         tool_ordering = print.tool_ordering();
         tool_ordering.assign_custom_gcodes(print);
+        float temp_max_additional_fan = tool_ordering.cal_max_additional_fan(print.config());
+        if(temp_max_additional_fan > max_additional_fan )
+                        max_additional_fan = temp_max_additional_fan;
         if (tool_ordering.all_extruders().empty())
             // No object to print was found, cancel the G-code export.
             throw Slic3r::SlicingError(_(L("No object can be printed. Maybe too small")));
@@ -2579,6 +2585,8 @@ void GCode::_do_export(Print& print, GCodeOutputStream &file, ThumbnailsGenerato
     this->placeholder_parser().set("retraction_distances_when_ec", new ConfigOptionFloatsNullable(m_config.retraction_distances_when_ec));
     this->placeholder_parser().set("long_retractions_when_ec",new ConfigOptionBoolsNullable(m_config.long_retractions_when_ec));
 
+    this->placeholder_parser().set("max_additional_fan", max_additional_fan);
+
     auto flush_v_speed = m_config.filament_flush_volumetric_speed.values;
     auto flush_temps = m_config.filament_flush_temp.values;
     for (size_t idx = 0; idx < flush_v_speed.size(); ++idx) {
@@ -3117,6 +3125,7 @@ void GCode::_do_export(Print& print, GCodeOutputStream &file, ThumbnailsGenerato
         //BBS
         config.set_key_value("layer_z",   new ConfigOptionFloat(m_writer.get_position()(2) - m_config.z_offset.value));
         config.set_key_value("max_layer_z", new ConfigOptionFloat(m_max_layer_z));
+
         if (print.config().single_extruder_multi_material) {
             // Process the filament_end_gcode for the active filament only.
             int extruder_id = m_writer.filament()->id();
diff --git a/src/libslic3r/GCode/ToolOrdering.cpp b/src/libslic3r/GCode/ToolOrdering.cpp
index e4616e07ee..6de65a5dd6 100644
--- a/src/libslic3r/GCode/ToolOrdering.cpp
+++ b/src/libslic3r/GCode/ToolOrdering.cpp
@@ -928,6 +928,22 @@ void ToolOrdering::cal_most_used_extruder(const PrintConfig &config)
     }
 }
 
+float ToolOrdering::cal_max_additional_fan(const PrintConfig &config)
+{
+    // record
+    float max_fan = 0;
+    for (LayerTools &layer_tools : m_layer_tools) {
+        std::vector<unsigned int> filaments = layer_tools.extruders;
+        std::set<int>             layer_extruder_count;
+        // count once only
+        for (unsigned int &filament : filaments)
+            if (max_fan < config.additional_cooling_fan_speed.get_at(filament))
+                max_fan = config.additional_cooling_fan_speed.get_at(filament);
+    }
+    return max_fan;
+}
+
+
 //BBS: find first non support filament
 bool ToolOrdering::cal_non_support_filaments(const PrintConfig &config,
                                                          unsigned int &     first_non_support_filament,
diff --git a/src/libslic3r/GCode/ToolOrdering.hpp b/src/libslic3r/GCode/ToolOrdering.hpp
index 1c92ef55b1..7f7fc6a6ce 100644
--- a/src/libslic3r/GCode/ToolOrdering.hpp
+++ b/src/libslic3r/GCode/ToolOrdering.hpp
@@ -246,6 +246,7 @@ public:
     // should be called after doing reorder
     FilamentChangeStats get_filament_change_stats(FilamentChangeMode mode);
     void                cal_most_used_extruder(const PrintConfig &config);
+    float               cal_max_additional_fan(const PrintConfig &config);
     bool                cal_non_support_filaments(const PrintConfig &config,
                                                   unsigned int &     first_non_support_filament,
                                                   std::vector<int> & initial_non_support_filaments,