The invention discloses a derrick flaw patrol robot. The derrick flaw patrol robot comprises a front trolley, a connecting structure and a back trolley. The front trolley is connected with the back trolley through the connecting structure. The front trolley comprises a front trolley frame, an antenna, a signal transmitter, a signal receiver, a moving camera, a front clamping drive mechanism, an electromagnet and a three-axis acceleration sensor. The back trolley comprises a back trolley frame, stepping motors, stepping motor drivers, a control device, a back clamping drive mechanism, an electromagnet and a power source device. The connecting structure comprises lead screws and round springs. The control device is connected with the signal transmitter, the signal receiver, the moving camera, the three-axis acceleration sensor, the electromagnets and the stepping motor drivers. The signal transmitter is connected with the antenna. The power source device supplies power to the whole system. By the adoption of the derrick flaw patrol robot, manual patrol is not needed, the labor resource is saved, and potential physical safety hazards are avoided, and the monitoring precision is improved at the same time. In addition, the derrick flaw patrol robot can conduct monitoring and feed back data in real time, and a monitor can conveniently conduct checking.