By constructing a colored multigraph model for automatically switched optical network(ASON) and using the strategy of comprehensive cost,a new algorithm of minimal comprehensive cost path is proposed.And combining the dynamic characteristics of group members,a dynamic multicast routing algorithm with multi-constraint(DMRMC) is presented.The proposed algorithm not only can finish multicast routing and wavelength assignment in one process,but also tries to make the comprehensive cost of multicast tree to be the least.Meanwhile,the number of wavelength conversions,the number of light-splittings and the number of wavelengths are optimized locally.Through simulation and analysis,it is proved that the proposed algorithm is effectively feasible,and achieves lower comprehensive cost and better blocking probability,compared with other algorithms which use the strategy of single cost.