In order to meet the demand of precise management on mechanization of straw returning to field operations, the difficulties were solved as follows: firstly, the area statistics of each landblock is hard. Secondly, the onsite verification needs a lot of people as well as lots of time. Finally, the manage department can not get the present situation on time. Therefore, it is in great demand to establish the precision management system for mechanized straw returning. The system integrated the Beidou satellite navigation and positioning system(BDS), the internet of things, geographic information systems and other new generation information technologies. The work carried out two parts. One part, the vehicle positioning terminal based on Beidou was established for agricultural machinery, which can realtime acquisite, and process the location and status data of agricultural machinery. The other part, the precision management system for mechanized straw returning was developed and implemented by using several functions including operation monitoring, landblock identification, area measurement, quality evaluation, index statistics and dispatching function, etc. The test results show that it can effectively control agricultural machinery operation trajectory, flexible scheduling, real time implementation of classified statistics and analysis, improve the efficiency of management of the returning operation. At the same time, the results reached the working precision in landblock identification and landblock area statistic, which can satisfy the demand of mechanization from straw to field operations.