Abstract:Through investigating population quantity of non-target biology after spraying Bt oil-based suspension agent in forest, we have researched change areas of diversity of insect community in pine forest and evaluated ecological security of biotic insecticide. The results showed that Bt oil-based suspension agent had stronger specificity which was mainly effective for Lepidopotera larva and inefficacy for other insects. At the same time, it reduced the quantity of pine caterpillar and kept the stabilization of diversity of insect community in forest.