In this paper, we propose the method for reducing out-of-order packets at handover event in LEO satellite networks. In LEO satellite networks, every communicating terminal handovers independently. Therefore, delay between terminals varies drastically within a short period. This drastic delay variation causes out-of-order packets and unnecessary fast retransmission of TCP. To avoid such delay variation, the proposed method makes a satellite to predict and control handover timing of connected user terminals. In the proposed method, two communicating terminals handover in a synchronized manner. By doing this, out-of-order packets at a handover can be reduced and this contributes to avoid occurrence of TCP's false retransmissions.