A rotary piston compressor comprises a cylinder block (100), an eccentric rotor group (200) being fitted in the chamber of the cylinder block, a shaft (2) and a separating means (40). The eccentric rotor group (200) comprises a cylindrical rotor (4) provided on the shaft (2) and rotatable therewith, and a collar (3) rotationally provided on the cylindrical rotor (4). The separating means (40) is used for separating the axially extended sealed chamber, which is formed between the outer peripheral surface of the eccentric rotor group (200) and the inner wall of the cylinder block (100), into an induction chamber (70) and an exhaustion chamber (71). Wherein, the separating means (40) comprises: a baffle (8) provided between the inner wall of the cylinder block (100) and the collar (3) provided on the outer periphery of the eccentric rotor (4), a contact member (7) provided between the baffle (8) and the collar (3) and contacted therewith, and a jointing element (6) connecting the contact member (7) to the baffle (8) and the collar (3) respectively.