A remote monitoring system for unmanned sowing operation of rapeseed direct seeding unit was designed by taking the Reeva 804 tractor and its equipped 2BYQ-8 air-fed rapeseed direct seeding machine as the test platform to solve the problem that it is difficult to display the field sowing quality information in real time and intuitively during the unmanned sowing operation of rapeseed direct seeding unit. The system consists of three parts including unmanned sowing platform， unmanned sowing data collection system and sowing quality monitoring cloud platform. Corresponding control strategies were designed to achieve unmanned sowing operation of the direct seeding unit through the electric and hydraulic modification of the gear， clutch， power take off （PTO）， and suspension mechanism of the Lovol 804 tractor. A vehicle mounted router was used to establish a local area network between the seeding monitoring terminal and the on-board computer to realize the fusion and synchronization of seeding data and navigation data. Data were transmitted to cloud platforms through network connections for data storage and real-time display. The cloud platform calculated the seeding quality data and its corresponding field location data， and generated the seeding status map of the field operation area based on the high-precision map on the web page. Results showed that the average lateral deviation of the unmanned sowing operation section of direct seeding unit was 0.037 m， with a maximum deviation of 0.125 m. The electric and hydraulic modification system operates stably and reliably， meeting the unmanned operation requirements of the direct seeding unit. The maximum data transmission time delay of the cloud platform communication did not exceed 100 ms under the 4G network conditions. The cloud storage data is complete without omission， the accuracy of field sowing detection of each sowing channel is not less than 96.16%， meeting the real-time and accuracy requirements of remote monitoring system. It is indicated that the system can realize the unmanned sowing operation of rapeseed oil direct seeding unit in the field and the accurate collection and intuitive display of sowing information in the operation area. It will provide reference for the remote monitoring of rapeseed sowing operation， the analysis and visualization of sowing data.