The invention provides a light source light spot detection method and device. The light source light spot detection device comprises a light source, a testing clamp, a diaphragm, an industrial cameraand an image processor. The method includes the following steps that detection preparation is conducted, position adjustment is performed for primary imaging, imaging micro adjustment is conducted, images are collected, and data is processed. The invention further provides a light source light spot detection device. Compared with the prior art, the light source light spot detection method and device realize that the method is simple, detection efficiency is high, accuracy is good, costs are low, and detection data provides reliable bases for the improved design of a product.