The aim of this study is to design a wearable sensor device and to optimize the position of the sensor attachment, which is one of the important factors for the prosthetic hand control based on the surface electromyography (sEMG). Through anatomical examination of the arm, the independence of the surface electromyogram acquired in each channel is increased and the signal to noise ratio (SNR) is also increased by signal processing. We introduce a study on the research trend and sensor position of the surface EMG-based prosthetic hand in Introduction. In body, the design and characteristics of the developed sensor are explained, and correlation analysis between each channel and finger force is performed by selecting the position of the sensor through anatomical examination of the arm. In conclusion, we use the correlation analysis result and find the optimal sensor location.