Abstract: In order to comprehensively evaluate the human body's functions of breathing, heart function and circulation metabolism under controlled conditions to diagnose respiratory and cardiac functions, a cardiopulmonary exercise test (CPET) system was developed. The system is divided into two parts:hardware and software. The hardware part includes measurement of six life information monitoring signals such as 12-lead ECG, respiratory mechanics, blood pressure, blood oxygen, carbon dioxide and oxygen. The software part realizes waveform display, storage and playback, et al. The experimental results show that the system is safe and reliable which provides reliable measurement parameters for evaluating human respiratory, cardiac function, circulation, metabolism and other functions. It has a good application prospect.