To shorten industrial robots' trajectory running time and reduce operating errors, a spline interpolation algorithm-based method for industrial robot work trajectory planning is proposed. First, a trajectory planning function for industrial robots is constructed using B-spline curves. Second, based on the curvature extremum point segmentation B-spline, independent S-shaped velocity planning is performed. The Simpson integration method calculates the curve length and determines the time span. Then, the S-shaped speed planning strategy implements independent speed configuration for segmented trajectories of industrial robots, achieving smooth transition speed control. Finally, the Cartesian coordinates of the interpolation points for the industrial robot's trajectory are calculated to complete the running trajectory planning. Test results show the proposed method can shorten trajectory running time to within 2 seconds and reduce trajectory error to within 0.3 cm.