One undesirable problem introduced by the Optical Multistage Interconnection network is crosstalk that is caused by coupling two signals with each other in switching element. One way to solve this problem is to avoid coupling two signals within the same switching element. But before any attempts, a method should be used to find out which message should not be in the same group. After finding conflicts and generating the conflict matrix, an algorithm is used to route the messages in different passes with respect to the conflict matrix. The purpose here is having less execution time. In this paper, four Heuristic routing algorithms are improved to have less execution time.