diff --git a/src/libslic3r/SupportMaterial.cpp b/src/libslic3r/SupportMaterial.cpp
index d251ccc8ac..13282b90d4 100644
--- a/src/libslic3r/SupportMaterial.cpp
+++ b/src/libslic3r/SupportMaterial.cpp
@@ -3286,7 +3286,9 @@ PrintObjectSupportMaterial::MyLayersPtr PrintObjectSupportMaterial::generate_raf
         const BrimType brim_type       = object.config().brim_type;
         const bool     brim_outer      = brim_type == btOuterOnly || brim_type == btOuterAndInner;
         const bool     brim_inner      = brim_type == btInnerOnly || brim_type == btOuterAndInner;
-        const auto     brim_object_gap = scaled<float>(object.config().brim_object_gap.value + object.config().brim_width.value);
+        // BBS: the pattern of raft and brim are the same, thus the brim can be serpated by support raft.
+        const auto     brim_object_gap = scaled<float>(object.config().brim_object_gap.value);
+        //const auto     brim_object_gap = scaled<float>(object.config().brim_object_gap.value + object.config().brim_width.value);
         for (const ExPolygon &ex : object.layers().front()->lslices) {
             if (brim_outer && brim_inner)
                 polygons_append(brim, offset(ex, brim_object_gap));
@@ -3389,7 +3391,12 @@ PrintObjectSupportMaterial::MyLayersPtr PrintObjectSupportMaterial::generate_raf
         if (columns_base != nullptr) {
         // Expand the bases of the support columns in the 1st layer.
             Polygons &raft     = columns_base->polygons;
-            Polygons  trimming = offset(m_object->layers().front()->lslices, (float)scale_(m_support_params.gap_xy), SUPPORT_SURFACES_OFFSET_PARAMETERS);
+            Polygons  trimming;
+            // BBS: if first layer of support is intersected with object island, it must have the same function as brim unless in nobrim mode.
+            if (object.has_brim())
+                trimming = offset(m_object->layers().front()->lslices, (float)scale_(object.config().brim_object_gap.value), SUPPORT_SURFACES_OFFSET_PARAMETERS);
+            else
+                trimming = offset(m_object->layers().front()->lslices, (float)scale_(m_support_params.gap_xy), SUPPORT_SURFACES_OFFSET_PARAMETERS);
             if (inflate_factor_1st_layer > SCALED_EPSILON) {
                 // Inflate in multiple steps to avoid leaking of the support 1st layer through object walls.
                 auto  nsteps = std::max(5, int(ceil(inflate_factor_1st_layer / m_support_params.first_layer_flow.scaled_width())));