Abstract: In view of the problems of low efficiency and poor accuracy of seedbed leveling in standardized seedling greenhouses, a working device of rice seedbed grader with double rotating blade structure was studied, the structural parameters and working parameters of the working device were determined, and the motion parameters and force of key components were analyzed. The analysis of Workbench software showed that the maximum stress of key components was 104.59 MPa; the maximum overall deformation was only 1.903 8 mm; and the natural frequency of the first 6th order was between 66.22-113.94 Hz, which meets the design requirements. The field test results showed that the maximum elevation difference of the seedbed bed decreased from 15.8 cm to 4.7 cm after operation, the standard deviation value of the relative elevation of the ground decreased from 3.95 cm to 0.98 cm, and the absolute difference after operation accounted for 92% of the measurement points with an absolute difference of less than 1.5 cm, which improved the bed surface leveling and met the needs of local shed seedlings.