The spatial variability of crop yield reflects the effects of environment and management factors on yield, and obtaining accurate yield spatial distribution information is the prerequisite for optimal input of resources on demand. In order to obtain spatial information on grain yield, a real-time monitoring platform was designed and developed for the spatial distribution of farmland grain yield based on the mobile terminal .The platform can realize the remote monitoring of the real-time position, operation status and yield data of combine harvester, and then analyze the spatial distribution of yield data. The platform consists of four modules, including data reception and storage, data transmission, data display and data analysis. Among them, the data reception and storage module is used to receive the operation status information packet such as the position of the harvester, the grain flow rate, the ascending speed, the barn temperature and humidity, and the cutting width. The data is analyzed and stored in the database. The data transmission module provides Web service for the mobile terminal, and extracts the corresponding data from the database for the front end call. The data display module can display the position and operation status of combine harvester in real time on mobile terminal. The data analysis module uses the ArcGIS Server GP service to create spatial distribution of grain yield. The testing results indicate that the monitoring platform is stable, and can display the yield spatial distribution information in real time.