Aiming　at　the　problem　of　low　control　accuracy　and　poor　stability　caused　by　the　controller　area　network　(CAN)　communication　time-varying　delay　during　the　rotating　speed　control　phase　of　the　gear　shift　process,　a　rotating　speed　closed-loop　control　mathematical　model　with　random　time-varying　delay　was　established,　and　the　method　of　using　fractional　PID　to　modify　the　frequency　response　curve　was　proposed,　which　improved　the　system＇s　adaptability　to　time-varying　delay.　Aiming　at　the　time-varying　characteristic　of　time-varying　delay　and　the　limitation　of　fixed-parameter　PID,　a　rotating　speed　control　algorithm　based　on　fuzzy　fractional　PID　was　designed.　Simulation　and　experiment　results　show　that　the　control　algorithm　achieves　better　effects.　©　2022,　Editorial　Department　of　Journal　of　Beijing　University　of　Technology.　All　right　reserved.