A detector for a welding deviator parameter of a weld joint of a submerged arc welded steel pipe comprises an equipment main body, equipment brackets, a ring light source, a CCD camera, an A/D converter, a DSP platform and a liquid crystal display screen; the equipment brackets are arranged on the both sides of the equipment main body, and the upper surface of the equipment main body is provided with the ring light source and the CCD camera; the CCD camera is arranged at the center of the ring light source; the lower surface of the equipment main body is provided with the liquid crystal display screen; the CCD camera in the equipment main body is connected with the DSP platform through the A/D converter, and the DSP platform is used for identification, analysis and calculation of digital images, and connected with the liquid crystal display screen; and the equipment brackets are used for clamping on the edges of the both sides of a welded pipe. According to the detector, the labor intensity of test personnel is reduced, and the measuring accuracy is improved; the influence of human factors is reduced, and the instrumentation measurement is achieved; the detector is widely applied to production inspection and quality supervision and inspection of steel pipes for oil and gas pipelines, and the quality and technology level of the steel pipes made in China are improved; and the purposes of speediness, high efficiency, objective and accuracy are achieved.