For people in the life of the measurement system of temperature and humidity of the new requirements, such as rapid response speed, high precision, high integration and so on. In order to meet the needs of the modern user's function and performance requirements, a temperature and humidity detection system based on STM32 and CAN bus protocol is proposed. The system realizes realtime and efficient transmission of data through CAN bus. Finally, the accuracy of the whole system is tested,the accuracy of the temperature reaches ±0.3℃, and humidity reaches ±2%RH. The test results show that the system has high accuracy and stable performance and it also can be quickly and efficiently.