The invention discloses a cloud computing simulation system and a cloud computing simulation method based on a simics system simulator, and relates to the field of cloud computing simulation. The simulation system comprises a plurality of data center simulation units, a network simulation unit and a plurality of terminal group simulation units, wherein the data center simulation unit simulates various nodes of a cloud computing data center; the network simulation unit simulates the transmission performance of an Internet protocol (IP) network and comprises an IP network simulation module and/or a DelayBox module based on ns2; and the terminal group simulation units simulate access of a plurality of terminals to a cloud computing platform and comprise pressure test tools Apache Jmeter and/or terminal group simulation modules based on ns2. On the basis of the simics system simulator, a network scene of the whole cloud computing is constructed with relatively low cost; simulation test research on the cloud computing is realized; the system construction period is shortened; the decision scientificity during system construction is improved; and the cloud computing simulation system and the cloud computing simulation method can be applied to various cloud computing platforms.