Multi-Constrained QoS routing in GMPLS (generalized multiprotocol label switching) network is to find an optimal path satisfying several constraints, such as bandwidth, cost and delay. The problem has been considered as a NP-Complete problem. Based on SRLG heuristic information, the paper provides a MPAS algorithm (Multi-constrained Precomputation Algorithm with SRLG), which includes the precomputation and searching procedures. The precomputation i s able to create and update the routing tables in each node. Then, the searching procedure can select an optimal path satisfying several constraints in the hierarchical architecture. The results of extensive simulation based on the self-similar traffic show that the corresponding methods can achieve satisfactory performance and efficiently solve the problem of multi -constrained QoS routing in GMPLS network.