Abstract: In view of the large-scale application of CAN Bus Technology in agricultural machinery, but there is a lack of agricultural machinery remote monitoring system combining can bus technology and Internet of things technology, which has the problems of high rent of special server and long development cycle of related software, a remote monitoring system of corn cultivator variable rate fertilizer applicator based on OneNet open platform is studied.The STM32103 main controller is used for data processing and conversion, and the BC20 wireless communication module is responsible for data transmission, with the help of OneNet platform, the PC end and mobile end can realize real-time remote monitoring of the speed, coordinates, fertilizer discharge shaft speed and other state parameters of the fertilizer applicator.The experimental results show that the whole system has low data transmission delay, stable performance, and the success rate of data transmission is more than 95%, which can meet the working requirements of complex field environment.The remote real-time monitoring of the state parameters of the variable rate fertilizer applicator for maize intercropping is realized.