The invention belongs to the technical field of automotive safe driving and particular to a monitoring and speed control method using an automobile safety belt. The method uses a speed sensor, an acoustic reminder, an alarm light and a sensing device, all of which are connected with an automotive ECU (electronic control unit). When a reel of the safety belt rotates or a tongue is inserted into a belt buckle during running of an automobile, the sensing device operates and transmits a safety signal to the automotive ECU, and the automobile runs normally. When the automotive ECU does not receives the safety signal sent by the sensing device, the speed sensor transmits current speed value to the automotive ECU, and the automotive ECU compares the speed value for determination. The monitoring and speed control method using the automobile safety belt has the advantages that the speed can be controlled in 100km/h by the method, utilization rate of the safety belt can be increased to the greatest extent, life and property safety of drivers and passengers are protected, and the method is more humane and more popular with car owners than the method which disables car running unless the safety belt is used forcibly.