The invention relates to a water corrosion resistance solvent-free polymer coating service lifer prediction method, which is characterized by comprising the following steps that: (1) a solvent-free polymer coating material is coated on a steel substrate so as to be adopted as a specimen; (2) the specimen is soaked in water with a temperature of 90 DEG C respectively for a certain days, and the specimen is taken out and is cooled to a room temperature after 1 h; (3) the coating surface of the specimen is gashed into square grids with a size of 15 mm*30 mm by using a knife, then a sharp-pointed knife is adopted to carry out prying stripping on the four corners of the square grid, and grading is determined according to wet adhesion of the coating, wherein the wet adhesion of the coating is the shedding condition; (4) when the specimen presents the grade 1, the soaking time (assumed to be m days) is determined, pluses 7 days, and then is multiplied by 3 to obtain an ideal service life (n years) of the coating, wherein n meets the following formula: n=(m+7)*3; and (5) the ideal service life of the coating is multiplied by an effect reduction coefficient (mu) to obtain a prediction service life (N years), wherein N meets the following formula: N=mun=mu*{(m+7)*3}, and the effect reduction coefficient value (mu) is 1 when n is less than 30, is 0.9 when n is more than 30, is 0.8 when n is more than 50, and is 0.7 when n is more than 70. With promotion and application of the method, engineering safety is easily achieved, and the method can further be adopted as an engineering accident analysis tool.