A new type of differential double-stator swing hydraulic motor,based on double stator structure,was introduced.Compared with the traditional swing hydraulic motors,it could provide various kinds of rotational speeds and torques under the same conditions of input flow rate and pressure.The operating principle and graphic symbols were described.The output speed and torque characters in multifarious connection modes were analyzed through single-acting differential double-stator swing hydraulic multi-motors.Then the differential connection modes and differential principles of differential double-stator swing hydraulic multi-motors were stated.Furthermore,the output speed and torque characters of doubleacting and triple-acting ones in multifarious connection modes were gotten.The interaction between output torque and the displacement ratio was studied.Finally,the internal leakage that influenced the volumetric efficiency was researched.The theoretical and experimental researches show that th