The present invention discloses a finger-clipped oximeter comprising an upper case (2) and a lower case (1), wherein one of the upper case (2) and the lower case (1) is provided with a guide post (12) which enables the upper case (2) and the lower case (1) to depart from and approach to each other vertically, the other of the upper case (2) and the lower case (1) is provided with a guide sleeve (13) which enables the upper case (2) and the lower case (1) to depart from and approach to each other vertically, and a return spring (9) is provided between an end of the guide post (12) and the case provided with the guide sleeve (13). One of the upper case (2) and the lower case (1) is provided with rockers (7, 8) which are used to facilitate the upper case (2) and the lower case (1) to depart from and approach to each other vertically, the other of the upper case (2) and the lower case (1) is provided with chutes (14, 15) which are used to facilitate the upper case (2) and the lower case (1) to depart from and approach to each other vertically, and ends of the rockers (7, 8) fit with the chutes (14, 15).