A fringe reflection measurement system with simple structure is developed to measure the surface of an angel lobster eye X-ray lens, and it is easy to operate. First, a fringe reflection image of the lobster eye lens whose size is 40 mm×40 mm is taken by a charged coupled device camera, and the slope error distribution of the lens surface is calculated. The root mean square (RMS) and peak-to-valley (PV) values of the lobster lens obtained by the fringe reflection measurement system are 0.81 μm and 6.34 μm, respectively. The measurement results of the proposed system are consistent with those of the Zygo interferometer. The standard deviations of the RMS and PV values obtained by repeated surface measurements are 0.017 μm and 0.11 μm, respectively. The feasibility of the fringe reflection measurement system for measuring the surface of an angel lobster eye X-ray lens is verified. Then, the X-ray focus imaging simulation is performed for the measurement of the surface error of the lobster eye lens based on the Monte Carlo method. The full width at half maximum of the diffuse focal spot caused by the surface error is approximately 0.23 mm, and the corresponding angular resolution is 2.11'. This optical measurement system provides a reference for the spherical forming of the lobster eye lens.