The invention discloses a hydraulic swing motor. The hydraulic swing motor is characterized in that two ends of a rotor blade are respectively provided with a sealing disc, the sealing disc comprises a front sealing disc and rear sealing disc, an outer diameter sealing groove and an inner diameter sealing groove are formed in the sealing dish, and the outer diameter sealing groove is internally provided with a third step seal; the inner diameter sealing groove is internally provided with a second step seal, a stator blade is provided with two oil inlets/outlets, and the two oil inlets/outlets are respectively communicated with a pressure chamber and an exhaust pressure chamber. The sealing effect between the pressure chamber and an absorption chamber of the swing motor or the swing blade pump is ensured under conditions of relatively high medium (oil) pressure and relatively working temperature, so that the service life of the motor is prolonged.