In order to solve the path planning problem of 6-DOF manipulator in workspace, an improved artificial potential field method combined with rapidly-exploring random tree(RRT)algorithm was proposed. Taking FANUC M-20iA industrial robot as the research object, the D-H parameters of each link were selected and a coordinate system was created to analyze its forward kinematics.The collision problem was transformed into the problem of the shortest distance between the center of the sphere and the axis of the cylinder. The potential function of the potential field method was improved,and RRT algorithm was used to make the manipulator jump out of the local minimum point when the manipulator entered the local minimum point, then the potential field method was used to plan the path to reach the target point. Finally, the improved algorithm was simulated in MATLAB. The simulation results show that using the algorithm, obstacles can be successfully avoided and the manipulator can run to the targets moothly.