Insecticide as well as preparation method and application thereof

The invention provides an insecticide as well as a preparation method and application thereof. The insecticide is prepared from insecticidal active ingredients, water, a foaming agent, a foam stabilizer and a synergist. When in use, the insecticide is added into the foaming device, the foaming device is used for preparing the insecticide into foam, and the foam is fed into a scene needing insect killing to complete insect killing. Through cooperation of the foaming agent, the foam stabilizer and the synergist, the foaming capacity and the foam performance of the insecticide can be effectively improved; when the insecticide is applied to cockroach and termite nests, due to the fact that foam of the insecticide can exist lastingly and stably, the contact time of the insecticide with sewers and termite nests is prolonged, the utilization rate of effective insecticidal ingredients is increased, and in actual use, the purpose of effectively killing pests can be achieved with a smaller dosage; the pollution to the