Turntable drive device of crane

A turntable drive device of a crane comprises a turntable, a hydraulic motor and a change valve; the power output of the hydraulic motor is connected with the turntable drive device; the change valve is a three-position four-way hydraulic change valve; and two routes of input ends of the change valve are connected with a power oil opening and an oil return opening of a hydraulic system respectively, and two routes of output ends of the change valve are connected with two routes of oil openings of the hydraulic motor through pipelines respectively. According to the turntable drive device of the crane, and the turntable can rotate to the left or to the right and stay at any position as required without any additional braking device, therefore, the operation is convenient.