The invention discloses a double-insurance locking mechanism regulating arm. The double-insurance locking mechanism regulating arm comprises a shell, a worm, a worm shaft, a controlling and regulating mechanism capable of regulating and limiting worm rotation, a fastening device and a clamping plate which is arranged outside the shell and connected with the shell through the fastening device, and the clamping plate is provided with a groove-shaped regulating mechanism which his used for conducting a screw shaft to regulate rotation by cooperating with tightness of the fastening device. According to the double-insurance locking mechanism regulating arm, the clamping plate is designed outside the shell, rotation of the head of the worm shaft is limited by the clamping plate, the braking clearance is precisely regulated, the fallback phenomenon generated in braking can be reduced, and potential safety hazards are eliminated; the clamping plate and the shell are fixed through a bolt, the structure is simple, installation is convenient, and the self-locking capability is very high.