The present invention discloses a gummosis protection therapeutic agent and a preparation method of the gummosis protection therapeutic agent, the weight percentages of the raw materials of which are 40 to 50 percent of 27 percent lipid film emulsifying agent, 0.4 to 0.6 percent of 40 percent flusilazole emulsifiable concentrate, 1.9 to 2.1 percent of additive, 0.1 to 0.3 percent of 20 percent naphthylacetic acid powder agent and 47.4 to 57.4 percent of 1 percent gentian violet. The preparation method of the present invention is to uniformly heat and mix the 27 percent lipid film emulsifyingagent with the 40 percent flusilazole emulsifiable concentrate and the additive in the water bath under 60 centigrade degrees to be made in to a mixed solution A; additionally to uniformly heat and mix the 20 percent naphthylacetic acid with the gentian violet in the water bath under 60 centigrade degrees until the 20 percent naphthylacetic acid is completely dissolved to be made into a mixed solution B; then to gradually pour the mixed solution A into the mixed solution B and to mix the solutions while pouring until the solution is uniformly mixed without layer division. The present invention has dual function effects of physically screening and preventing the disease and penetrating to sterilize and to cure the disease, which has high cure rate, long medicinal effective period and obvious prevention effect.