Aiming　at　the　drawbacks　of　the　heavy　workload　and　lengthy　calibration　cycle　of　transmission　control　unit　(TCU)　development,　a　fast　optimizing　and　test　method　of　clutch–clutch　shift　calibration　parameters　is　developed　based　on　the　“V”　development　process.　A　controlled-object　simulation　model　of　a　six-speed　automatic　transmission　(6AT)　is　established,　and　the　shift　calibration　parameters　and　shift　quality　evaluation　system　are　studied.　Therefore,　a　model-in-the-loop　(MIL)　calibration　platform　for　key　calibration　parameters　and　evaluation　indicators　in　the　shift　process　is　constructed.　By　setting　the　optimization　target　of　evaluation　indicators,　the　initial　calibration　parameters’　ranges　are　reduced.　Finally,　the　TCU　is　flashed　with　the　optimized　calibration　parameters,　and　a　hardware-in-the-loop　(HIL)　test　system　is　built　to　verify　the　shift　quality.　The　same　shift　quality　verification　test　is　carried　out　in　the　vehicle.　The　test　results　show　that　the　application　of　the　MIL　simulation　platform　can　enable　the　batch　simulation　analysis　of　eight　key　shift　calibration　parameters,　gradually　refine　the　initial　rough　interval,　and　ensure　shift　quality.　The　shift　calibration　parameters　are　cross-validated　in　multiple　development　links,　and　the　dependence　on　vehicle　calibration　is　greatly　reduced.　The　development　cycle　is　effectively　shortened　to　less　than　6　months.　©　2024　by　the　authors.