With the discovery that double-stranded RNA (dsRNA) could result in gene silencing (RNA interference, RNAi) in Caenorhabditis elegans, scientists began to exploit this RNAi technology for the study of gene functions, in order to improve crop resistances and genetic breeding. In this paper, the principle of RNAi technology is introduced, and the differences between the RNAi and traditional transgenic technology are discussed. Based on the potential miss-target effect of RNAi technology, we analyzed the potential risks of RNAi technology from improving plants, target organisms and ecological environment, which provided reference for risk assessment of RNAi technology. Because there are still risks in RNAi technology, in order to maintain ecological diversity and safeguard people's personal safety, we should establish a safety evaluation method. Therefore, we summarize the evaluation schemes of environmental safety and food safety of RNAi genetically modified crops. RNAi technology may play an important role in reducing pest densities, increasing rice yield, reducing planting costs, reducing chemical pesticide pollution. However, there are still risks in this technology. Further supervision and research are needed to establish a sound ecological evaluation system so that RNAi technology can play a role in agricultural production.