Abstract: For the existing methods, it will cost a lot of time and computation to solve time-optimal trajectory planning problem of industrial robots along fixed path. To solve this problem, the maximum phase speed profile is obtained firstly by using velocity constraint inequality in joint space. Then, the necessary maximum constraint speed curve is obtained by using joint acceleration/torque constraint inequality. By intersection operation for the above two maximum speed curves, the maximum speed curve under multiple constraints is obtained. Finally, the time optimal trajectory is obtained by correcting the maximum speed curve under multiple constraints with the pruning/shooting algorithm. The efficiency and real-time performance of the proposed algorithm is demonstrated by experiment.