Abstract: To quickly and economically manufacture a prosthesis that fits the shape of a stump of a prosthesis user. A prosthesis shape data generation system provided includes: a stump shape data acquisition unit that acquires stump shape data, which is shape data on a stump of a living body; and an estimated prosthesis shape data generation unit that performs an estimation processing by inputting the stump shape data to a machine learning model that has previously learnt a correspondence between a stump shape and a shape of a part or a whole of a prosthesis that fits the stump shape, thereby generating estimated prosthesis shape data that is shape data on a part or a whole of a prosthesis that fits the stump of the living body.