High accuracy track tracing is a challenging task in paddy fields due to uneven grounds as well as wet soil conditions, thus restricting the development of autonomous rice drill seeder in China. For the purpose of overcoming the obstacles in application of autonomous rice drill seeder in paddy fields, a path tracking algorithm with high accuracy used for steering control during straight traveling in uneven mud paddy fields is introduced in this paper. Combining lateral deviation and heading angle deviation as feedback, a nonlinear steering control model is developed in the algorithm. Integrators are added to the nonlinear control model to eliminate the steady-state errors. Moreover, the velocity of vehicle is also taken into consideration in this model to improve the accuracy of path tracking. Attitude variation incurred by uneven fields and side slipping make it troublesome for the tractor to acquire the accurate position of the vehicle from Global Positioning System (GPS) whose antenna is located on the top of the tractor cabin, which as a consequence limits the accuracy of path tracking. In order to solve this problem, the influence caused by the roll angle and the pitch angle of the vehicle on position coordinates given by GPS are taken into account when the vehicle is on a slant. Afterwards, the algorithm for improving the position accuracy is illustrated in detail in this paper. The overall control scheme was implemented and experiments were carried out to verify the effectiveness of the algorithm in arable paddy fields. With the introduced algorithm, the autonomous rice drill seeder is able to follows the predefined path, makes a turn at the boundary line of the paddy filed, and moves to the next desired straight path.