The invention discloses an image collecting system of a shaft detecting device and an image collecting method of the image collecting system. The image collecting system of the shaft detecting devicecomprises a base, a moving translation stage and a to-be-tested fixing tool rack. The moving translation stage is arranged on the back surface of the base, the to-be-tested fixing rack is arranged onthe front surface of the base, the moving translation stage is connected with a supporting rack, a lens supporting rack and a light source supporting rack are arranged at the two ends of the supporting rack, the lens supporting rack and the light source supporting rack are symmetrically arranged, a camera is fixed to the lens supporting rack, a light source is fixed to the light source supportingrack, and a lens of the camera is opposite to the light source in a center parallel mode. The image collecting system of the shaft detecting device further comprises a PC machine, a moving controllerand an image processor, the PC machine is electrically connected with the moving controller and the image processor, the moving controller is electrically connected with the moving translation stage,and the image processor is electrically connected with the camera. According to the image collecting system of the shaft detecting device and the image collecting method of the image collecting system, measurable parameters are complete, the automation degree is high, the shaft-like parts are subjected to parameter measuring by using an image processing technology, the measuring precision is high,and the situation of damaging due to part contacting is avoided.