The invention discloses an anti-theft alarm system for radar speed measurement and a control method of the anti-theft alarm system. The system comprises a main control module, a detection module, an alarm module, a heating module and a GPS/GSM wireless communication module. The input end of the main control module is connected with the detection module, the output end of the main control module is connected with the alarm module and the heating module, and the communication end of the main control module is in wireless connection with a background control platform through the GPS/GSM wireless communication module. According to the control method, whether equipment is damaged or stolen or out of power is judged through the detection module, and then whether the alarm module is started or not and whether an alarm message is sent or not are judged. Compared with the prior art, the anti-theft alarm system for radar speed measurement is small in size, a communication card can be additionally arranged for remote communication through the communication module of the system, and indirect control can be achieved through the speed measurement equipment by means of communication with the speed measurement equipment. Meanwhile, a special glass demisting function is added, and the situation that snapshot is affected when water mist appears on anti-blasting glass of the speed measurement equipment in winter is avoided.