Cloud is one of the important factors in the field of meteorology forecasting and navigation and so on. Therefore, it is important to measure cloud. As one of the important meteorological parameters, the cloud cover has become an important part of meteorological observations. So far, the measurement of cloud cover mainly relies on visual observation, which leads to large deviations because of various factors. Measuring the cloud cover is an important application of laser ceilometer. An automatic inversion algorithm of cloud cover of laser ceilometer is proposed in this paper. The purpose of the algorithm is to construct a two-dimensional image of time and cloud height based on the ceilometer measurements only from a single point. The cloud cover is calculated according to the ratio of time occupied by clouds. The comparative experiments show that the algorithm can more accurately calculate the cloud cover information, and it is of great practical value for laser ceilometer.