Inner diameter measuring scale for prosthetic socket

An inner diameter measuring ruler for an artificial limb socket comprises a hollow depth ruler, a rotating shaft rotatably penetrates through the depth ruler, the lower end of the depth ruler is fixedly connected with a ruler box, the rotating shaft penetrates through the ruler box and then is fixedly connected with a rotating ruler body through a connecting shaft, and one end of a steel ruler is fixedly connected to the rotating ruler body. A steel ruler winding groove is formed between the outer wall of the rotating ruler body and the inner wall of the ruler box, a plurality of first axial blind holes are formed in the end face of the ruler box in the circumferential direction, the first axial blind holes penetrate through the inner wall of the ruler box in the circumferential direction and communicate with the steel ruler winding groove, and first rotating columns are rotationally installed in the first axial blind holes correspondingly. The bottom surface of the rotating ruler body covers the axial blind