On the basis of research on surface electromyography（sEMG）signal

a myoelectrical controlled prosthetic hand system is designed.It includes electromyography（EMG）signal acquiring and conditioning system and the prosthetic hand control system.Through the signal acquiring and conditioning circuit

the EMG signal is amplified

filtered and notched

A/D is converted and feature calculated by MSP430F149 microcontroller whose power consumption is low.The single-chip microcontroller combines the EMG signal with the feedback signal of the tactile and slip sensor

to control the velocity and the direction of the motor

so as to let the prosthetic hand to do corresponding action.The signal displayed on oscilloscope is compared with the action of prosthetic hand.The result shows that the design is reasonable and effective.