Abstract: In order to improve the intelligent degree of the micro tiller and meet the increasing demand of "replacing people with machines", a crawler type automatic navigation electric micro tiller suitable for gardening environment was designed. First, the NVIDIA Jetson Orin nano equipped with the robot operating system (ROS) is used as the main control to establish the navigation control system and communicate with the bottom layer of the electric micro tiller. Secondly, based on Kalman filter and extended Kalman filter, according to the influence of gross error on extended Kalman filter state estimation, an improved robust adaptive extended Kalman filter is proposed to effectively correct single error and multiple special errors, so as to limit and reduce the negative impact of gross error on Beidou guidance PVT (position, velocity, time) solution to the greatest extent, and improve the positioning accuracy and signal stability. The shuttle path planning method was used to carry out the navigation test and record the positioning data, and the positioning error standard deviations of x, y, z axes corresponding to different positioning data processing methods were compared. The results show that the improved robust adaptive extended Kalman filter proposed in this study has certain advantages in improving the positioning accuracy and signal stability. The box Behnken test was designed with vehicle speed, tillage depth and rotary blade speed as test factors and soil fragmentation rate as evaluation index; The test results were analyzed by variance, and the regression model of evaluation index and test factors was established. In order to improve the broken soil rate as the optimization goal, the operation speed, tillage depth and rotary blade speed were optimized. The optimal parameter combination was obtained as operation speed 1.4 km/h tillage depth 6 cm and rotary blade speed 234 r/min. The field tillage experiment showed that the broken soil rate could reach 95.8%, which showed that the crawler type automatic navigation electric micro tiller had better operation quality and could meet the requirements of rotary tillage in horticultural environment.