The invention discloses a control method of robot intelligent welding. The method sequentially comprises the following steps that image marking is carried out on a welding point of a part to be welded; an image recognition system is built, and the image mark of the welding point is recorded into the image recognition system; the image recognition system is matched with a welding robot; unification and standardization are carried out on the image recognition system and a three-axis coordinate system inside the welding robot; the part to be welded is placed to a welding platform of the welding robot; the image recognition system and the welding robot are started; the image recognition system detects the image mark, the same as the recorded mark, on the part to be detected, and a three-dimensional coordinate of the part to be detected is obtained; the welding robot obtains a three-dimensional coordinate of a welding gun on a welding arm; the three-dimensional coordinate of the obtained image mark is compared with the three-dimensional coordinate of the welding gun, and vector operation is carried out; and a mechanical arm is controlled to move according to a vector operation result. The control method has the advantages that the improvement cost is low, improvement can be directly carried out on existing equipment, a self-inspection function is achieved, and working stability is high.