The development and maintenance of domain knowledge based system need a lot of manual operations, and with the increasing amount of contents in the system, it is more and more difficult to find the relevant information. The keyword based search usually can not return the accurate result. To solve these problems, this paper proposes a semantic knowledge system with ontology engineering approach. It can acquire data and update knowledge system with less human efforts, and the feedback mechanism can help the knowled gesystem automatically correct the inaccurate metadata. The semantic query improves the keyword based query and returns the answer accurately. The customized interactive user interface is implemented with proper technology to display the knowledge hierarchy and data relationship, and improves the efficiency of the system user.