To study the characteristics and synchronous performance of new hydraulic synchronous multi-motor (Referred to as hydraulic multi-motor), the hydraulic multi-motor is used as synchronous motor in synchronous circuit. The functions of new synchronous circuit and traditional synchronous circuit are compared and ana1yzed, and based on the hydraulic multi-motor structure, the factors affecting on its volume efficiency are studied. The three hydraulic cylinder synchronous system constituted by hydraulic multi-motor prototype is composed to carry out the experiments, and the synchronous performance is verified. Theoretical analysis and experimental results show that the new hydraulic multi-motor not only can completely realize the function of traditional synchronous motor with fewer components and higher precision (1.0%-1.7%), but also can achieve different diameter cylinder synchronization.