Abstract: Based on the statistical data of reliability problems of dozens of small satellites already launched by the DFH Satellite Co. Ltd., the distribution of the reliability problems of small satellites in the flight model phase is studied. The proposed distribution model as a double logrithmic distribution is found to be in good agreement with the data, with a small difference between the fitted curve of the first flight satellite and that of the subsequent ones. A method for the screening rate assessment based on the accumulated power-on time of small satellites is put forward to decide when and whether the satellite can be allowed to put into service.