Abstract: For the trajectory planning of the end of the manipulator, when using the straight-line formula for straight line planning, there is the problem of inaccurate calculation results and large calculation amount in the micro controller. The Bresenham algorithm commonly used in computer drawing is introduced. Relying on the designed mechanical arm model, the mathematical model of Denavit-Hartenberg(D-H)parameters is established for the mechanical arm, and the forward and inverse kinematics are solved by using the pose analysis matrix and plane analysis method with simplified degree of freedom(DOF); analyzing the motion of each joint and the effect of applying the algorithm from the simulation of the mechanical arm model using the Bresenham algorithm; make the improvement and simulation with the step compensation optimization for the adverse effects caused by the algorithm. In the simulation results, the manipulator can run according to the planed straight-line trajectory. The algorithm avoids the division operation. After the algorithm is optimized, the speed requirement when starting is reduced by nearly one-half; compared with the linear analytical planning method, it reduces the calculation time and avoids the error of the end of the mechanical arm. Bresenham algorithm has the characteristics of precise planning and small amount of calculation in the straight-line trajectory planning of the robotic arm. The step compensation optimization has improved the defects of sudden speed change at startup.