In order to improve the accuracy and automation level of the air conditioning and fresh-keeping process for fresh agricultural products, a set of remote monitoring and gases distribution for fresh-keeping system was designed, which realized the control of raw gas flow, concentration and mixing ratio based on embedded PID control algorithm and mass flow controller. 4G network was used as the bridge of remote data transmission, 4G DTU was selected as the network data transceiver, and the remote monitoring function of mobile clients was realized by application on the phone. The gas parameter sensing layer, data network transmission layer and control operation application layer were set up in the system structure. Based on the requirements of remote monitoring of gas distribution system, Modbus RTU program was embedded in PLC to ensure the communication between DTU and PLC. TCP protocol was used as a bridge in order to enable data transmission between it and the cloud server. At the same time, remote monitoring and system maintenance on mobile client was realized based on application software in the phone. According to the test of system stability, accuracy and communication performance, the error of distribution volume fraction was 0.22% when the distribution was stable, the average error was reduced by 91.67% compared with the traditional method. Moreover, the gas distribution speed was increased by about 50%, which greatly improved the working conditions and production efficiency of the gas distribution site. It provided technical support for further perfecting the automatic gas distribution production line of fresh agricultural products.