Data transmission method based on QPI bus and computer system

The invention provides a data transmission method based on a QPI bus and a computer system. The computer system comprises an interaction unit connected with another computer system through the QPI bus, a dividing unit used for obtaining a data space from the computer system through dividing, an establishing unit used for establishing the mapping relation between the data space of the computer system and the data space of another computer system, a processor used for sending a QPI message containing a first address of the data space to a system controller, and the system controller used for mapping the first address into a second address of the data space of another computer system according to the mapping relation and sending a QPI message containing the second address to another computer system. By the adoption of the scheme, data transmission efficiency between interconnected systems is improved.