With the microcomputer improving and multimedia and wideband network developing. the I/O bandwidth requires more and more. The last standard bus, for example, ISA, EISA and MC can not be satisfied with the demand of the modern technology. In this case, the PCI bus appears, and become the master standard bus. Now there are two methods to realize the PCI Controller circuit, which are the special chip and the programming logic chip. The PCI system structure is introduced,and a PCI Bus Controller is Fealized based on the I/O transmit through using a Lattice1032E chip. Which has proved successful by application.