For　the　flat　plastic　parts　with　the　size　range　of　200　to　1300　mm,　the　structural　parameters　decision　model　of　injection　mold　gating　system　is　established　in　this　paper.　Firstly,　the　relationship　between　the　warpage　and　the　structural　parameters　of　gating　system　is　fitted　by　Kriging　model,　and　the　minimum　warpage　is　optimized　by　genetic　algorithm　(GA)　to　obtain　the　best　structural　parameters.　Secondly,　the　best　structural　parameters　of　gating　system　corresponding　to　16　groups　of　plastic　parts　are　taken　as　samples,　and　the　relationship　between　the　structural　parameters　of　gating　system　and　the　size　parameters　of　plastic　parts　is　established　by　Kriging　model.　In　addition,　K-means　is　used　to　reduce　the　number　of　the　structural　parameters　of　gating　system　from　5　to　2,　in　order　to　improve　the　accuracy　of　decision　model.　Finally,　the　size　parameters　of　plastic　parts　are　input　to　the　decision　model　to　obtain　the　structural　parameters　of　gating　system.　Through　the　verification　of　mold　flow　analysis　experiment,　the　structural　parameters　of　gating　system　obtained　by　this　method　meet　the　design　requirements　and　can　effectively　shorten　the　structural　design　cycle　of　injection　mold.