With the change of modern people’s life, more and more middle-aged and elderly people suffer from sarcopenia due to lack of exercise, which leads to higher incidence of muscle atrophy. In order to determine the risk of sarcopenia early, biological impedance method was used to detect the human body. Based on AFE4300, a set of four-electrode human bioelectrical impedance measurement system is designed, which is based on STM32 single chip microcomputer and consists of AFE4300 module, digital grip module, serial port module, power supply module and host computer, etc. Using AFE4300 module to measure the impedance of human limbs, fitting limbs skeletal muscle content, and the use of digital dynamometer to grip strength measurement of the subject, combined with limb skeletal muscle content and grip strength value size, contrast and optimize the sarcopenia’s judgement criteria in the country, risk profile can be divided into three levels: low risk, moderate risk and high risk. Experiments on people over the 18 years old show that the system can reflect the risk of human sarcopenia better.