The invention provides a class of 4-halogenated methyl-1,2,3-thiadiazole compounds and a preparation method and application thereof, relating to heterocyclic compounds containing 1,2,3-thiadiazole, which have the following chemical general formula as shown in the specification of the invention. The invention discloses the general formula, the synthesis method of the compounds, application of the compounds used as insecticides, disinfectants, antiphytoviral agents and plant activators and the process for preparing insecticides, disinfectants, antiphytoviral agents and plant activators by mixing the compounds with agriculturally acceptable additives or synergists; the invention also discloses the application of combining the compounds with commercial insecticides, disinfectants, antiphytoviral agents and plant activators to prevent and treat diseases, pests, virus diseases in agriculture, forestry and horticulture, and the preparation method of the compounds.