Oracle RAC architecture is a new technology which began to be used from Oracle9i. It is a kind of high-availability technology,and also is the core technology of Oracle database support for grid computing environment. The performance of RAC mainly depends on the performance of Cache Fusion. Through analyzing the principle of Cache Fusion and the reasons of generated wait events, and taking the advantage of Partition technology to scatter data request of instance, it can reduce the pressure of Cache Fusion, and fully play the performance of the RAC.