Disclosed are a trifluoromethyl alkenylphosphonate derivative and preparation method therefor. The preparation method comprises the following steps: dissolving an acetylene derivative, an iodine compound, and a phosphorus reagent in a solvent for reaction at the temperature from the room temperature to 100° C. to obtain the trifluoromethyl alkenylphosphonate derivative. In the present invention, the acetylene derivative is used as a starting material, and the raw materials are easily available and diversified; products obtained by using the method of the present invention have various types and can be directly used and also used for other further reactions; moreover, the method disclosed in the present invention has the advantages of short steps, mild reaction conditions, simple reaction operation and post-treatment processes, and high yield, and is suitable for large-scale production.