Abstract: In this paper, the problem of dynamic routing under the hose uncertain model for the full-mesh optical network architecture is considered. A novel dynamic routing algorithm-LBADF (Load Balancing with Adjustable Distribution Fraction) based on Valiant load balancing is proposed. LBADF algorithm can instantly adjust distribution fraction in Valiant load balancing according to the number of the spare wavelengths on the links to optimize the performance of the network. Computer simulation results show LBADF algorithm has the lower blocking probability for the whole network than that of VLB (Valiant Load Balancing) algorithm, which has the fixed distribution fraction. And the maximum blocking probability for all the node pairs in the network can also be reduced correspondingly in LBADF.