This paper focuses on the hardware and software design method of a new type of high efficient temperature and humidity testing cabinet. As the hardware core is based on the STC12C5616AD MCU, the entire hardware system is simpler and more reliable. By using sectional measurement of temperature and humidity, adopting expert PID control algorithm and using hardware and software compensation measures, the system dynamic and static quality and control precision is further improved. The system cabinet with a unique inner and outer double-loop structure improves the system efficiency and energy saving effect. Furthermore, the use of touch screen as input and output device, which is simpler to operate and more eye-catching, meets the different needs of consumers.