To improve spatial target tracking precision and stability of mobile photoelectric tracking equipment, state estimation and prediction of the target with high accuracy is necessary. An improved error-space estimate method with time correction is presented to estimate and predict the state of spatial target accurately for the mobile tracking equipment. By the method, measurement without satisfying validity and veracity is obtained by scanning, and time error is calculated and corrected with correlation analysis of actual measurement and offline estimation sequence of spatial target orbit. From new offline estimation and actual measurement, estimation of target state with high accuracy is obtained by ordinary error-space estimate method to guide the tracking system to perform steadily. Experiment results show that comparing with the spatial target state estimation without time correction, the one of the method presented is with higher accuracy, and estimation error increases more slowly along with prediction steps.