The invention discloses an image viewing diagnosis device and a viewing diagnosis method of railway rail side equipment and belongs to the technical field of rail side equipment fault detection. The device comprises vehicle-mounted equipment and exterior lifting equipment, wherein the vehicle-mounted equipment is placed in a cabinet; and the exterior lifting equipment comprises a linear array camera and a laser range finder that are welded at the bottom of an inspection vehicle. The viewing diagnosis method comprises the steps of utilizing GPS positioning, shooting the 5T rail side equipment by using a scanning technique of the linear array camera when the inspection vehicle passes by the 5T rail side equipment, allowing an image server to perform data processing after passing by a detection object, finding out an object body image to be viewed, performing automatic fault recognition on a part with high fault possibility, and manually checking and verifying the image at last. The device and the method have the advantage that all the problems in exterior conditions of the 5T rail side equipment can be monitored safely, efficiently and objectively.