The utility model provides a well drilling turnplate reactive torque release control device which comprises magnetic blocks, a disc, a hall sensor, a support, a counting relay and an electromagnetic valve, the well drilling turnplate reactive torque release control device is characterized in that the disc is provided with a through hole, and the disc is fixedly sleeved on a center shaft of a turnplate; the outer wall of the disc is provided with grooves which are evenly distributed along periphery, and the magnetic blocks are placed in the grooves; the hall sensor detects the magnetic blocks so as to output an impulse signal to the counting relay; a power supply is connected with coils of the electromagnetic valve through the counting relay, and an air source is connected with an air inlet end of the electromagnetic valve and an air inlet end of a brake normally closed gas detector of the turnplate through air pipes; and the output end of the electromagnetic valve is connected with a control end of the brake normally closed gas detector of the turnplate through an air pipe wire, and an air outlet end of the brake normally closed gas detector of the turnplate is connected with a turnplate brake clutch. The well drilling turnplate reactive torque release control device provided by the utility model can automatically control the inverse braking position of the well drilling turnplate, the turnplate is reversed to the set position, and the turnplate is automatically controlled to stop rotating, thereby safely releasing reactive torque.