With the development of intelligent mobile devices and social media, more and more end-user-oriented applications have emerged. How to fully understand the needs of end users and reduce the risk of software projects have become an urgent problem. Among all kinds of software projects, the development of open source software projects is special, which reflects in the extensiveness and multi-level of participants, as well as the multi-facetedness and instability of user needs. Based on the assessment of project maturity, a setup and assessment model of open source software project is proposed, and the method of maturity evaluation and the process of open source software project setup based on maturity are introduced in detail. The setup and assessment process is demonstrated with a concrete project scenario.