In order to improve network routing performance, a QoS (quality of service) multicast routing algorithm based on genetic ant colony optimization algorithm was proposed and designed. Firstly, an adaptive frequency conversion acquisition strategy was designed to collect network and node information, in order to obtain the status of the network and nodes and provide data support for subsequent routing optimization. Secondly, the path cost was calculated, the minimum path cost as the optimization objective was set, a QoS multicast routing optimization model was established, and relevant constraints was set. Finally, a genetic ant colony optimization algorithm was proposed by combining genetic algorithm and ant colony algorithm to solve the above model, output the optimal path, and complete routing optimization. The experimental results show that the proposed algorithm can effectively reduce path length and cost, improve search efficiency and routing request success rate, and optimize the routing delay jitter.