The invention discloses a method and device for detecting the parallelism of a sensor image plane and a lens interface end face with simple and rapid detecting operation. The method comprises the steps of A, plane reflection mirror placement; B, light source illumination; C, light and shadow acquisition capture; D, parallelism calculation. The method is simple, quick, easy to operate and low in interference, adopts the principle of beam back-folding, and can achieve the parallelism between the image plane and the lens interface end face of an automatic light and shadow collector when a camerato be tested is not energized; the parallelism between the finished camera image plane and the lens interface end face is detected, the camera is graded according to a detection result, an unqualifiedproduct is removed, the imaging consistency of the same camera is ensured, and a defective product of the same camera with poor imaging quality is prevented from being produced; high-precision quantitative index data is provided for facilitating subsequent improvement of production processes, the product manufacturing quality is improved, and high-quality imaging cameras are manufactured.