Abstract: A high-precision human metabolic measurement system is designed. The system uses STM32F103 as the main control chip to acquire oxygen, carbon dioxide and flow signals to calculate four quantitative indicators: oxygen consumption(V_O2), carbon dioxide production(V_CO2), respiratory entropy(RQ) and resting energy metabolism(REE), and finally uses an upper computer to display the calculation results.In this paper, the signal acquisition circuit design was carried out for the oxygen sensor, carbon dioxide sensor and flow sensor, and the validity of the device was verified with the American machine MGCDiagnositcs using Bland-Altman analysis method, and the results showed that the four parameters of V_O2,V_CO2, RQ and REE of both devices fell in the agreement interval of more than 95%. The device thus provides accurate metabolic measurements and offers an effective tool for the field of general health and clinical nutrition support in China.