The invention discloses a motor stopping control mechanism which is suitable for a winch of a boom hoist. The winch is provided with a driving device, a winding device, a braking device and a control device. The control device is provided with the motor stopping control mechanism to control the operation of quickly stopping running of a motor when the winch is at an upper limit position or a lower limit position. According to an electrical structure of the motor stopping control mechanism, a motor control loop is connected with a contactor in series between a motor protection breaker and a frequency converter, a control loop of the contactor is provided with a limit unlocking knob, and the limit unlocking knob is connected with an upper position limit switch and a lower position limit switch in parallel. The motor stopping control mechanism can improve the product performance of the boom hoist.