For detecting space debris in the high orbit, a telescope with wide field of view (4°), large relative aperture (1∶1.32) and broad wavelength (500 nm to 800 nm) is obtained. The telescope, whose clear aperture is Ф750 mm, consists of primary mirror and refractive corrector group. The surface type of primary mirror is parabolic, and the refractive corrector group includes one ellipsoid lens and three spherical lenses. The advanced methods of optical elements measurement and whole system are introduced respectively. Firstly, the figure error of spherical lens is measured using template method. A compensation test method of null lens is used to test the hyperbolic primary mirror and ellipsoid corrector lens. Next, when the corrector lens group is aligned, the whole corrector lens group is tested making use of a new spherical mirror method. And at last, it is adopted to measure the optical telescope with collimator test in the room and with nature star observation outdoors. All of the measurement results are satisfying the requirement of design. The figure errors of spherical lenses are less than 0.1 fringe in the first step, the figure errors of primary mirror and ellipsoid lens are less than λ/30 (RMS), and the wavefront error at the third step is less than λ/30 (RMS). After measuring the whole telescope optical system in the room, the 80% encircled energy is within 2 pixels, at the side of that, when observing the stars outdoors, the 80% encircled energy is also within 2 pixels in the whole field of view, 4° diagonal.