Bacterial insecticides are the largest and most widely used microbial insecticides in domestic research and development. The varieties used in the study were Bacillus thuringiensis, Pseudomonas spp., Japanese beetles and spherical bacillus, of which Bacillus thuringiensis is the most representative species. Bacillus thuringiensis (BT) is a kind of important insect pathogen which can produce the companion Spore crystal toxin, the insect host spectrum is widespread, is one kind of gastric toxicity insecticide. Bacillus thuringiensis has a different degree of toxicity to various agricultural pests, such as helicoverpa armigera, tobacco and green worms, silver worm, Spodoptera litura, Spodoptera exigua, small tiger, rice longitudinal roll roller, corn borer, diamondback moth and tea caterpillar, which have good effect on forest pest insects. In addition, it can be used to control mosquito larvae and stored-grain moth pests.