The utility model discloses a tower crane overturning-prevention safety monitoring device, comprising a tension force sensor, an amplitude vibration stroke stopper, a rotary table stroke stopper, a lifting relay, an amplitude relay, a rotary table relay, a jacking relay and a buzzer; the tower crane overturning-prevention safety monitoring device further comprises a programmable logic controller; the tension force sensor, the amplitude vibration stroke stopper and the rotary table stroke stopper are connected to the input port of the programmable logic controller by a cable, and the lifting relay, the amplitude relay, the rotary table relay, the jacking relay and the buzzer are connected to the output port of the programmable logic controller by a cable; the device not only can collect the angle of the rotary table, the amplitude and the lifting weight information of an acquisition tower machine in the operation process, but also can effectively detect the inclination angle information of the tower body of the tower crane, the information can be input to the programmable logic controller to be analyzed and judged comprehensively, so as to timely judge, display, alarm and lock the dangerous overturning actions caused possibly.