In the process of programming and source code reuse, since simple keyword-based code search often leads to inaccurate results, an accurate search method for source code was proposed. Firstly, according to the objectivity and uniqueness of syntax and semantics, the syntactic structure and semantics of I/O of a function in source code were considered as part of a query. Such query should be submitted following a regularized format. Secondly, the syntactic structure, semantics of I/O, keyword-compatible match algorithms along with the reliability calculation algorithm were designed. Finally, the accurate search method by combining syntactic and semantic queries was realized by using the above algorithms. The test result shows that the proposed method can improve Mean Reciprocal Rank (MRR) by more than 62% compared with the common keyword-based search method, and it is effective in improving the accuracy of source code search.