In this paper, we conduct research on the construction and robustness testing of SaaS cloud computing data center based on the MVC design pattern. The SaaS software needs to experience the strict test before the issue. For all this, because is very difficult to forecast in the future all possible network users' to the service condition of SaaS system, therefore is also hard to conduct the completely thorough test to the complex SaaS software. What test method with can realizes to carry on the unceasing test and confirmation at the beginning of project to the design of SaaS system, thus dodges the mistake that discovers the potential problem, when is constructs the SaaS system needs the issue of key consideration. The reliability of the software is based on the reliability of the software data. In order to collect the reliability data of the software, a system with software error reporting, analysis and basic correction functions should be established. According to the requirements of the industry standard, the software error reporting, reliability data collection, analysis and processing rules are completed, and the reliability data of the software testing phase is collected accurately and completely. This paper starts from the MVC pattern to propose the new testing paradigm that is effective.