In order to achieve automatic welding of casing welds in complex industrial environments, a casing weld visual identity method is proposed. Firstly, the pipe is detected by combining grayscale characteristics and color characteristics. Secondly, the weld potential regions are obtained by the morphological operation. Finally, weld seam identification is realized based on the positional characteristics of the casing weld on the copper pipe. Experimental studies verified the effectiveness of the method in complex environments.