Abstract: High-efficiency and low-toxicity pesticides can play a vital role in plant pest control and food safety. Traditional pesticides cannot fully meet the production needs of modern agriculture in recent years, due to the different degrees of pollution and environmental issues. It is very necessary to replace traditional pesticides with more efficient and environmentally friendly pesticides. Nanopesticides can be expected to serve as the promising potential candidate in the development of nanotechnology. The high efficiency and low residue can greatly contribute to agricultural pest control. In this review, the two types of nanopesticides were first introduced and processed using function nanotechnology, in order to obtain the nanoscale particles. The first type was to directly process the active ingredients of the pesticides into the nanoscale particles, which belonged to the non-carrier nanopesticides. Among them, the direct and indirect types were divided from the non-carrier nanopesticides, in terms of their action. The direct type of nanopesticides was used to directly control the pests or microorganisms in the form of direct death, while the indirect type of nanopesticides was to indirectly control the diseases and pests after stimulating the plant metabolism and resistance. The second type was to use the nanocarriers, such as the organic polymers and liposomes, to load the pesticide-active components. The carrier-type nanometer pesticides were prepared after adsorption, coupling, and encapsulation. Non-carrier nanopesticides included metal and metal oxide particles, inorganic particles, nano-gels, nano-micelles, and nano-dispersions. Carrier nano pesticides include carrier drugs that are prepared from different nanomaterials, such as polymers, and liposomes. Secondly, one summary was made on the application and behaviors of different types of nano-pesticides. In addition, a comparison was also made between the advanced nanopesticides over the traditional pesticides in agricultural applications. The nanopesticides were characterized by the slow-release and intelligent drug delivery response to the controlled release. The short efficacy and easy dispersion in the use of traditional pesticides were solved for the long-term and large-scale production under the controllable release. Thirdly, the biosafety of the nanopesticides and environmental safety were also evaluated as the agricultural drugs. A critical review was then made on the biosafety effects of the nano pesticides on animals, plants, microorganisms, and the environment, especially the soil environment from multiple perspectives. In theory, the nanopesticides normally share small or insignificant biosafety effects on different organisms, indicating better biosafety, or excellent selective toxicity, compared with traditional pesticides. Only lethal toxicity was observed on the target microorganisms or pests. There was no significant toxicity to other organisms. Nevertheless, there were still some gaps in the biosafety research of nanopesticides. Finally, the outlook was given for the prospects of the nanopesticides. Development standards were also required to evaluate the biosafety of nanopesticides for the safe dosage in industry. More importantly, the current research on the nanopesticides was mostly in the laboratory stage. The large-scale production and application of nanopesticides were then realized to balance the advantages and biosafety of nanopesticides, compared with traditional pesticides. The practical development of the current nanopesticide industry was summarized to provide theoretical and technical support for the design of efficient nanopesticides. The advanced technologies of nanopesticides can greatly contribute to sustainable and modern agriculture.