Abstract: Industrial robots have been popularly used in modern production because of the advantages of high efficiency, high production quality, and satisfactory environmental adaptability. The research on trajectory planning is the pillar of motion control for industrial robots and directly controls their work quality. To comprehend the research techniques of industrial robot trajectory planning thoroughly, first, various existing research methods are categorized according to diverse planning spaces and optimization goals. Second, the characteristics and applicable fields of basic trajectories, such as lines, arcs, and polynomial curves, are presented, and the methods for optimizing time, effect, and energy consumption, as well as the present challenges and limitations, are examined and elaborated. Lastly, the conclusion is that multiobjective optimal trajectory planning based on actual working conditions, machine-learning-based trajectory planning, multirobot trajectory planning, dynamic obstacle avoidance in trajectory planning, real-time trajectory planning based on intelligent perception, and trajectory planning based on virtual reality technology will be the development trends of industrial robot trajectory planning research.