Abstract: To address the insufficient characterization of the positioning accuracy error transfer mechanism and the difficulty in implementing reliability evaluation under small-sample working conditions for domestic industrial robots, a reliability analysis method for industrial robot positioning accuracy based on meta-action decomposition is proposed in this paper. Taking the HSR-JR605 6-degree-of-freedom serial robot as the research object, the whole machine is first decomposed into six single-degree-of-freedom meta-action units via the "Function-Movement-Meta-Action" decomposition method, and static and dynamic displacement error models of each meta-action unit are established using the DH kinematic model. Secondly, an error transfer model from meta-actions to the end effector is constructed based on multi-body kinematics and the error Jacobian matrix. Subsequently, the interval convex set model and volume ratio method are introduced, and numerical calculation of positioning accuracy reliability is completed. Finally, simulation verification is carried out through the MATLAB Robotics Toolbox. The results reveal that the forward kinematic model is validated to be accurate, and consistent end-effector pose values are obtained from theoretical calculation and simulation. The deviation between the calculated values of the error transfer model and the simulation outputs is limited to ≤0.001 mm, and the deviation between the reliability obtained by the convex set model and the Monte Carlo simulation results is controlled within 3%. The error transfer laws can be clearly characterized and the reliability of positioning accuracy can be quantified by the proposed method, and theoretical and methodological supports are provided for the accuracy design and reliability simulation of industrial robots.