Abstract: In the construction of nuclear power engineering, there are a wide variety of pipe fittings. The marking of traditional nuclear-grade pipe fittings mainly relies on manual adjustment of the focal length and marking area of laser equipment, which leads to high marking error and low working efficiency. To tackle this problem, this paper designs an automatic marking production line based on intelligent robots. This paper conducts an in-depth study on the overall design of the intelligent robotic automatic marking production line, mechanical clamping and rotation control of cylindrical pipe fittings, conveyor feeding of irregular pipe fittings, automatic positioning technology of robotic arms, as well as laser marking and automatic inspection systems. The system adopts a line-scan camera paired with a laser lens to realize precise marking on cylindrical pipe fittings. Combined with area-scan cameras and laser displacement sensors, automatic positioning and focal length adjustment are realized for irregular pipe fittings. The production line integrates full-process stations including automatic inspection, manual color marking coating, automatic drying and offline finished product storage. Experimental results verify that the system has remarkable advantages in improving marking speed, marking accuracy and intelligence level, which provides a practical feasible solution for the automatic marking of nuclear-grade pipe fittings.