RNA interference (RNAi) is a post-transcriptional gene silencing mechanism that is triggered by double-stranded RNA (dsRNA) and results in the degradation of homologous transcripts. RNAi technology has been developed as a powerful tool for genetic screens to analyze gene function in various organisms. Construction of large-scale species-specific RNAi library and further RNAi mutant library is important strategies for functional genomics research. So how to construct RNAi libraries simply and efficiently is becoming a key question in gene function research. In the review, representative strategies for RNAi library construction and their advantages and potential disadvantages were summarized.