RNA interference (RNAi) is a physiological phenomenon that endogenous gene occurs specific degradation after transcription, which widely exists as an immune mechanism against the viruses in organisms. The core mechanism of RNAi in Caenorhabditis elegans has been determined, but there exists an alternative systematic RNAi pathway in insects which is distinct from C.elegans. The homologous proteins of transmembrane SID-2 have not been found in insects yet, in addition, the RNA-dependent RNA Polymerase (RdRP) doesn′t locate in Drosophila melanogaster instead of other enzymes with similar function. The efficiency of RNAi varies not only with the target genes and the choice of doublestrand RNA (dsRNA), but also with the insects′ developmental state and the dose of of dsRNA intake. With the identification of the characteristics of RNAi in insects, the application value of RNAi has been gradually showing. In recent years, silencing the target gene by means of RNAi technology facilitates the development of gene function research. Additionally, RNAi is also widely used for the research on resistant genes in notorious pests. The latest study suggests that RNAi combining with the second generation sequencing technology can screen a lethal sequence to nonmodel insects, which speeds up the pace of producing biopesticides used for agricultural insect pests control by RNAi technology.