A prosthesis system driven by surface electromyography（sEMG） is introduced

aiming at serving for amputees with high-level amputation. The prosthesis movement is controlled by users’ motion intention

which is derived by corresponding sEMG signals.The whole system includes three subsystems: A prosthesis structure with an elbow joint

a wrist joint

and a hand; a hardware control platform

including a main control board

three driver boards

and five sEMG collection modules. Pattern recognition algorithm based on linear discriminant analysis（LDA）.The parameters of LDA are gotten by online training.Motion intention is identified based on LDA with the collected sEMG signals. Subsequently

the prosthesis is controlled by the recognition output of LDA. The performance of the prototype is verified on healthy subjects.