Multi-days orbit of BeiDou Satellites is gotten by the routine method of stacking observation data at present.And moreover,the dynamic model of BeiDou Satellites is not perfect because of the little running time,which also limits the precision of multi-days orbit.The method of multi-days BeiDou satellite orbit combination is present.In this method,normal equation stacking is used to combining some consecutive one-day BeiDou satellite orbits to one multi-days orbit,which can improve calculation efficiency.And meanwhile,pseudo-stochastic pulse is used to compensate the deficiency of dynamic model and improve the precision of multi-days orbit.The analysis shows that it is pseudo-stochastic pulse at the one-day boundary that improves the precision of BeiDou satellite orbits obviously in orbit combination.And the tangential and normal precision is improved more than the radial precision.The orbit precision of GEO and IGSO is improved more than that of MEO.The precion of BeiDou satellite orbit can improve by extending the orbit arc with certain limits,and the result is mostly obvious in the tangential direction.