The problem about the parallel traffic migration in recovery of the optical network based on path computation element is studied under the condition that the backup lightpaths cannot be setup using present available resources without traffic migration. A mathematical model is established, and the parallel traffic migration is realized. A heuristic algorithm is provided to obtain the order of restoration in parallel traffic migration,which is composed of dependence graph partition and lightpath sorting by minimizing the max number of the required resource of disrupted connections algorithm. The simulations show that minimizing the max number of the required resource of disrupted connections algorithm can significantly shorten the duration of the traffic migration in recovery with acceptable cost.