In recent years, because of their advantages in coverage and throughput compared to traditional fiber and mobile networks, satellite networks have garnered increasing attention. However, satellite networks have limited resources such as storage, power, and frequency bands. Therefore, how to maximize network transmission capacity under limited communication resources is a key to the practical application of satellite networks. To enhance the throughput of the satellite network, we have devised a multicast satellite network that incorporates network coding. Additionally, we have further bolstered the network capacity by optimizing its topology and refining the routing of information flow. In order to find a better topology structure, we design a Genetic Algorithm based topology construction method which decode the topology as the chromosome and finding topologies with higher performance by mimicking biological genetic meritocracy. Ultimately, the simulation outcomes demonstrate that the introduced method substantially outperforms traditional approaches in augmenting the network’s capacity.