A transmission assembly for a surgical robotic system, comprising: an input base having a first end and an opposing second end, the first end configured for connection with a drive mechanism; a guide transmission disposed on an outer circumferential surface of the input base; an output base having a third end and an opposing fourth end, the third end located closer to the first end than the fourth end; an axial energy storage member configured to store energy during movement of the input base and the output base toward each other under the action of an external force and to release, upon removal of the external force, the energy to drive movement of the input base and the output base away from each other; an axial limiting assembly configured to limit a maximum displacement of the input base and the output base from each other, wherein the output base is configured to cooperate with the guide transmission so that when the input base is driven by the drive mechanism to rotate, the guide transmission causes the output base to rotate in synchronization with the input base, wherein the third end of the output base is an open end, and the output base defines a cavity in which the second end of the input base is inserted, wherein the guide transmission is defined by an external extension of the outer circumferential surface of the input base, and an inner wall of the cavity is provided with a mating internal groove that matches the guide transmission, characterized in that: the axial limiting assembly comprises a first axial limiting sub-assembly, the first axial limiting sub-assembly comprising a third limiting stopper and a third stopper, the third limiting stopper provided on the outer circumferential surface of the input base, the third stopper provided on an end face of the output base at the third end, wherein the cavity of the output base is provided with a receptacle channel which matches the third limiting stopper so as to allow axial movement of the third limiting stopper, and upon the third stopper coming into interaction with the third limiting stopper, the output base is stopped from further axially moving away from the input base. an input base having a first end and an opposing second end, the first end configured for connection with a drive mechanism; a guide transmission disposed on an outer circumferential surface of the input base; an output base having a third end and an opposing fourth end, the third end located closer to the first end than the fourth end; an axial energy storage member configured to store energy during movement of the input base and the output base toward each other under the action of an external force and to release, upon removal of the external force, the energy to drive movement of the input base and the output base away from each other; an axial limiting assembly configured to limit a maximum displacement of the input base and the output base from each other, wherein the output base is configured to cooperate with the guide transmission so that when the input base is driven by the drive mechanism to rotate, the guide transmission causes the output base to rotate in synchronization with the input base, wherein the third end of the output base is an open end, and the output base defines a cavity in which the second end of the input base is inserted, wherein the guide transmission is defined by an external extension of the outer circumferential surface of the input base, and an inner wall of the cavity is provided with a mating internal groove that matches the guide transmission, characterized in that: the axial limiting assembly comprises a first axial limiting sub-assembly, the first axial limiting sub-assembly comprising a third limiting stopper and a third stopper, the third limiting stopper provided on the outer circumferential surface of the input base, the third stopper provided on an end face of the output base at the third end, wherein the cavity of the output base is provided with a receptacle channel which matches the third limiting stopper so as to allow axial movement of the third limiting stopper, and upon the third stopper coming into interaction with the third limiting stopper, the output base is stopped from further axially moving away from the input base. the axial limiting assembly comprises a first axial limiting sub-assembly, the first axial limiting sub-assembly comprising a third limiting stopper and a third stopper, the third limiting stopper provided on the outer circumferential surface of the input base, the third stopper provided on an end face of the output base at the third end, wherein the cavity of the output base is provided with a receptacle channel which matches the third limiting stopper so as to allow axial movement of the third limiting stopper, and upon the third stopper coming into interaction with the third limiting stopper, the output base is stopped from further axially moving away from the input base.