A multifunctional operating platform with four-wheel independent drive was designed and an autonomous navigation system was constructed based on industrial computer-underlying controller coordination to solve the problems of insufficient path safety and driving oscillation caused by narrow plots and frequent turns in hilly orchards.The A^* algorithm was improved by introducing dynamic weighting， multi-level safety distance constraints and turning penalty， and compared with the standard A^* algorithm through simulation.The results showed that the improved version reduced the number of searched nodes by 40.3% and decreased the number of turns from 16 to 10.A full-coverage path planning strategy for inter-row operations in orchards was further developed based on the improved A^* algorithm.A fuzzy-crab composite control method was proposed based on the kinematic characteristics of the lateral motion capability of platform.The fuzzy inference was used to dynamically adjust the look-ahead distance to achieve adaptive switching between crab mode and four-wheel active steering mode based on the consistency criterion between the target direction and the vehicle heading.The results of field experiments verifying the performance of the autonomous navigation system in an orchard showed that the average absolute deviation of the fuzzy-crab composite control under straight-path tracking conditions was 0.092 m， about 55.6% lower than that of the pure pursuit algorithm.The maximum lateral deviation and the average absolute deviation under variable-curvature path conditions decreased from 0.220 m to 0.152 m， and from 0.061 m to 0.048 m， respectively.The average absolute lateral deviation in the full-coverage autonomous navigation test in the orchard was 0.086 m， and the system continuously and stably completed autonomous driving tasks at channel ends and during channel switching.It is indicated that the constructed autonomous navigation system and the proposed planning and composite tracking methods can effectively improve the executability of path， the accuracy of tracking， and the continuity of operation in narrow-channel scenarios of hilly orchards.