Abstract: To evaluate the variations in the installation precision caused by the gravity differences between orbital and ground environment, a statistical analysis was carried out on the variation in equipment installation precision of twenty-seven launched small satellites under both no-load and full-load conditions in the ground environment, respectively. The linear regression relationship and parameter estimates of the lognormal distribution model were obtained. The results show that the relative error between the mean variation value and the measured value for the installation precision of spacecraft equipment under both no-load and full-load conditions did not exceed 10.6%, indicating that the lognormal distribution model can represent the variation distributions of spacecraft equipment installation precision under both conditions. The above study may provide a reference for the on-orbit equipment installation control.