With the development of microprocessor, emulation accelerator based verification has become the most effective system verification method. And the system frequency is one of the most important indexes of the emulation acceleration system. Based on the engineering application of the system verification to a homemade high performance microprocessor FT-X on a ASIC emulator, research was done by tuning the compile parameters assisted with compile results analysis. The acceleration mechanism of ASIC accelerator was analyzed. And then, the effect of domain number, normal register design mapping method, special register design mapping method on the system emulation frequency was studied. The results show that it's not a good idea to increase the domain number as much as possible, because there exists a sound range of memory size when the design under test is fixed. And the system emulation frequency was increased sharply by the application of forcible mapping method to some special blocks on the other hand.