A modularized prosthesis leg cover quickly covers a prosthesis leg and does not affect bending or stretching motion of a knee joint part of the prosthesis leg, thus preventing damage to the knee joint part of the prosthesis leg. Thus, the modularized prosthesis leg cover includes a thigh module, which can be mounted to a thigh socket of the prosthesis leg, a lower leg module, which can be fastened to a calf pipe of the prosthesis leg, and a patella module, which can be rotatably assembled with the lower leg module. The prosthesis leg cover, which is formed by assembling the modules, is covered with a skin module, which is made of a stretchable fiber. The respective modules are provided as prefabricated modules. A method of manufacturing the prosthesis leg cover is also provided.