The invention discloses a method for increasing seepage prevention reliability by sealing a dam surface seepage prevention film partition. The method includes the steps that a dividing line of the damface partition is prearranged; a fastener is mounted along the prearranged dividing line; a seepage prevention film is sprayed on the dam surface; the fastener is disassembled, and a compress part ismounted at the position where the fastener located; the compress part is fixed by the fastener; seepage prevention materials are sprayed on the surface of the fastener and the compress part, and a fastener pressing strip protective film is formed. According to the method, the problem of failure of whole seepage prevention due to the fact that the seepage prevention film is prone to falling off locally or in large area in the prior can be solved, the cost can be saved, the work efficiency can be improved, and the reliability of a seepage prevention body can be enhanced.