Solar array is a power source of spacecraft, which is often damaged by the impact of micrometeoroids and space debris, resulting in the decrease of output power of solar array. The degradation law of volt-ampere characteristic for spacecraft solar arrays under orbital debris hypervelocity impact is investigated by using a two-stage light gas gun. The volt-ampere characteristics of the solar arrays under different impact velocities, projectile diameters and impact positions are studied. A total of 12 shots are carried out, of which 5 shots are invalid due to the impact of the projectile carrier on the specimen, and 7 shots are valid. The experimental results show that the diameter, impact velocity, and impact position of the projectile all have a great influence on the volt-ampere characteristics, and the damage morphology generated by the ground simulation test is in line with the in-orbit flight test results. The relationship between the failure area of the solar arrays and the area of the spalling area, the perforation area, the kinetic energy of the projectile as well as the impact position are analyzed. It is found that the ratio of failure area to peeling area is between 7 and 37, and the ratio of failure area to perforation area is between 50 and 150. The failure area in the center of the solar cell is significantly larger than that on the edge or at the connection of the solar cell. Failure area of solar array $ \Delta {S}_{\mathrm{S}\mathrm{A}} $ and the cube root of kinetic energy E( $ E=\mathrm{\pi }\rho {d}^{3}{v}^{2}/12 $ ) is consistent. In order to establish the accurate equation of power loss area with projectile diameter and impact velocity, in this paper it is assumed that there is a power exponential relationship among them, and then solve the undetermined coefficient by the data fitting method. Finally, we establish the power loss $ {\Delta P}_{\mathrm{m}\mathrm{a}\mathrm{x}} $ equation and failure area $ \Delta {S}_{\mathrm{S}\mathrm{A}} $ equation suitable for domestic solar array. The equation will be $ {\Delta P}_{\mathrm{m}\mathrm{a}\mathrm{x}}=0.047d{v}^{2/3} $ , $ \Delta {S}_{\mathrm{S}\mathrm{A}}=260d{v}^{2/3} $ when the impact occurs in the center of the cell, and $ {\Delta P}_{\mathrm{m}\mathrm{a}\mathrm{x}}=0.033d{v}^{2/3} $ , $ \Delta {S}_{\mathrm{S}\mathrm{A}}=180d{v}^{2/3} $ when the impact occurs on the edge or at the connection of the solar cell. The prediction error of the equation is in a range of 13.3%, and the average deviation is 7.6%. This equation can be used to describe the function relationship between the power loss or failure area of the solar arrays and the diameter, impact velocity and impact position of the projectile under the condition of 0° impact angle. The research method in this paper can be used as a reference for the performance degradation assessment of Chinese spacecraft solar panels under the hypervelocity impact of orbital debris, the established power loss equation and failure area equation can predict the law of power decline and failure area of solar array caused by space debris, and the results have important application value for Chinese aerospace engineering.