The invention discloses a medicament for treating colpoxerosis and a preparation method thereof. 1,000 grams of gel is prepared from the following raw materials by weight: 10 to 20 grams of Rebamipide, 5 to 8 grams of Carbomer, 4 to 5 grams of sodium hyaluronate, 200 to 500 grams of polyethylene glycol 400, 1 to 2 grams of Edetate disodium, 18 to 22 grams of polysorbate 80, 1 to 10 grams of lactic acid, 1 to 3 grams of low polylactic acid, a proper amount of sodium hydroxide and the balance of water. The preparation method comprises the following steps of: (1) taking the Rebamipide for later use; (2) adding the polyethylene glycol 400 and the polysorbate 80 into the Rebamipide in the step (1) to obtain medicinal liquid for later use; (3) adding water into the Edetate disodium for later use; (4) mixing the polyethylene glycol 400 and the low polylactic acid uniformly by adding water; (5) adding the Carbomer and the sodium hyaluronate into the step (4) to form a gel matrix for later use; and (6) adding the lactic acid into the medicinal liquid to obtain the gel preparation. After the medicament for treating colpoxerosis is used for a period of time through vaginal administration, the colpoxerosis can be cured, so that the defects of the known technique can be overcome.