The invention discloses a vehicle speed control mechanism for a bullet loading vehicle. The vehicle speed control mechanism comprises a pedal; the middle of the top end of the pedal is hinged to a pedal base through a pedal shaft; the pedal base is fixed on a frame; a vertical swing arm is fixedly connected to the middle of the pedal shaft; a driving rod is hinged to the top end of the swing arm; the other end of the driving rod is hinged to a shift rod outside a throttle controller; a vertical speed limiting slotted board is fixedly connected onto the driving rod; a brake handle and a cover plate are arranged on the throttle controller; a speed limiting handle is hinged to the front end of the cover plate; a speed limiting pull rod is hinged to the bottom end of the speed limiting handle; a rotating shaft perpendicular to the speed limiting pull rod is fixedly connected to the right end of the speed limiting pull rod; and the front end of the rotating shaft is inserted in a sliding chute in the middle of the speed limiting slotted board. The vehicle speed control mechanism solves the problem that a conventional bullet loading vehicle is poor in running continuity, poor in form stability, and poor in smoothness, and has the advantages of being high in degree of automation, convenient to operate, and convenient and fast to maintain.