To solve anycast routing problem with multiple QoS constraints, a improved hybrid algorithm which combines genetic algorithm and ant colony algorithm is proposed. In the initial period of hybrid algorithm, genetic algorithm was used to distribute pheromones in links and code and optimize control parameters of ant colony algorithm. Through judgment function, this algorithm can judge the time to combine the genetic algorithm with ant colony algorithm, and initialize the pheromones and start the ant colony algorithm at the last period of hybrid algorithm. To avoid hybrid algorithm falling into local optimal solution, a mutation operator was introduced in algorithm hybrid to update local pheromones of new path produced by mutation operation and reduced pheromones concentration on optimal path in time. The NS2 simulation results show that this algorithm can commendably solve the anycast routing problem with multiple QoS constraints, and its performance is better than other two algorithms.