Agricultural modernization has become an inevitable trend of global agricultural development. The traditional greenhouse monitoring system has limitations, which cannot detect and deal with the abnormal environment in the greenhouse in time. In response to the above problems, this paper designs a greenhouse environment monitoring system based on STM32. The hardware part of the system uses STM32 as the main control module. The LD3322 speech recognition sensor is used in the speech module. Temperature and humidity sensor detection module using DHT11 digital sensor; Soil moisture using waterproof DS18B20 digital sensor; The actuator is controlled by a relay module. In addition, the LORA module is used in the wireless communication module, so that users can remotely monitor the situation of the greenhouse environment. In the light acquisition part of the software, the Kalman filter algorithm is used to analyze and process the data, and the serial communication protocol is used to transmit the collected data to the host computer. Through experimental debugging, the system realizes the function of speech recognition control and environmental temperature and humidity detection. The experimental results show that the greenhouse environmental monitoring and control system has high stability and reliability, can effectively solve the problems existing in the traditional greenhouse monitoring, and has certain application prospects and promotion value.