In recent years， the growing number of Low Earth Orbit （LEO） satellites and their enhanced capabilities have enabled LEO constellations to undertake a wider range of in-orbit missions， resulting in exponential growth in satellite data transmission volumes. Emerging Laser Communication （LC） technology， with its higher bandwidth advantage， significantly improves the efficiency of Inter-Satellite Link （ISL） data transmission. However， LC-based inter-satellite communication first requires alignment between the transmitting and receiving antennas， a process that incurs considerable time overhead. Furthermore， the limited number of laser transceivers onboard satellites increases communication latency， while unreasonable laser routing and link planning strategies can further exacerbate delays. To address these challenges， this study investigated the satellite routing communication link planning problem considering laser antenna alignment overhead， and formulates it as a Mixed Integer Linear Programming （MILP） model to minimize total communication time. As the problem was proven to be NP-hard， a low-overhead approximation algorithm named Relay Satellite Laser Routing （RSLR） was proposed. The performance of RSLR was compared with two baseline algorithms： Average Latency-based Persistent Routing （ALPR） and Minimum Hop Earliest Arrival （MHEA）. Experimental results show that the RSLR algorithm reduces communication latency by 10.3% and 12.5%， respectively， compared to ALPR and MHEA， confirming its effectiveness in lowering delays in satellite data transmission.