In this paper, we focus on the need for two approaches to optimize producer and consumer synchronization for auto-parallelizing compiler. Emphasis is placed on the construction of a criterion model by which the compiler reduce the number of synchronization operations needed to synchronize the dependence in a loop and perform optimization reduces the overhead of enforcing all dependence. In accordance with our study, we transform to modify and eliminate dependence on iteration space diagram (ISD), and carry out the problems of acyclic and cyclic dependence in detail. we eliminate partial dependence and optimize the synchronize instructions. Some didactic examples are included to illustrate the optimize procedure.