Detecting device of free surface lens

A detecting device of a free surface lens comprises a light source generator, a lens group, a light dot array coder and a planar array image sensor, and is characterized in that the parallel light source generator (1) comprises a light source and a projection optical system guiding the projection light come from the light source along a projection light path, the lens group (2) enables an incident monochromatic light beam to be beam expanded to become a parallel light beam sent to the clear aperture of a to-be-tested lens(4), and the light dot array coder (3) is arranged between the lens group (2) and the to-be-tested lens(4); the to-be-tested lens(4) is the free surface lens, and the planar array image sensor (5) is a more than 5-mega-pixel planar array image sensor. The detecting device of the free surface lens of the utility model has the advantages of being novel in design, compact in structure, reasonable in detection step design and simple in operation, and being able to detect the whole surface vertex