The invention discloses a car paint spraying robot assembly in the technical field of car paint spraying. The assembly comprises a paint spraying room, the top of a guide rail walking mechanism is fixedly provided with a robot arm assembly, a spraying head assembly is arranged at the right end of the robot arm assembly, the spraying head assembly is connected with a colored paint storage box and avarnish storage box through two sets of connection hoses, the right end of the guide rail walking mechanism is provided with a rotating disc mechanism, infrared heating assemblies are symmetrically arranged on the left side wall and the right side wall of an inner cavity of the paint spraying room, two draught fans are fixedly arranged on the top of the paint spraying room, and a control device is further arranged on the outer side wall of the paint spraying room. One robot is used for carrying out free point selection spraying on five faces and thirteen parting surfaces on the surface of a car, the spraying quality and the material use rate are improved, operation and maintaining are easy, the equipment use rate is high, the spraying track is precise, coating uniformity is improved, manual cost is saved, and the work efficiency can be improved.