The invention relates to a rotary hydraulic control system. The rotary hydraulic control system comprises a rotary reversing valve (3) and a mode switching device, wherein working oil ports of the rotary reversing valve (3) communicate with working cavities of a rotary motor (1) correspondingly, and the rotary reversing valve (3) is used for controlling starting and stopping as well as the rotating direction and the rotating speed of the rotary motor (1) during rotation; and the mode switching device communicates with the rotary reversing valve (3), a main pressure oil source and a pilot pressure oil source and is used for conducting switching between a normal rotary mode and a micromotion rotary mode. In the micromotion rotary mode, the mode switching device enables pressure oil of the pilot pressure oil source to serve as working oil of the rotary motor (1) so that the rotary motor (1) can be driven to rotate, and meanwhile, pressure oil of the main pressure oil source is made to serve as control oil of the rotary reversing valve (3) to drive the rotary reversing valve (3) to reverse and adjust the opening degree of the valve. When the rotary hydraulic control system is switched to be in the micromotion rotary mode, the pilot pressure oil source can provide small and stable oil supply pressure for the rotary motor, the stationarity of the rotary motor during micromotion and rotation is ensured, and the micromotion performance of a rotary mechanism is effectively improved.