The invention relates to a method for predicting the washout service life of an oil well sand control screen. The method comprises the following steps: performing sand control screen indoor washout experiment for a sand control screen used in a target oil well, and acquiring experimental data; drawing a variation curve of experimental pressure along with experimental time, finding the experimental time that the experimental pressure is reduced suddenly on the curve, testing the screen mass loss at the experimental time point, and confirming a critical point that the sand control screen is subjected to washout damage; fitting experimental data, and confirming a washout service life calculation equation of the sand control screen used in the target oil well; on the basis of the critical point that the sand control screen is subjected to washout damage, calculating the washout service life of the sand control screen under the conditions of different flow velocities of fluid and liquid sand-containing concentration, and drawing a sand control screen washout service life prediction chart; according to the oil deposit production allocation of the target oil well and the well completion sand control screen length, calculating the flow velocity on the surface of the sand control screen, confirming the concentration of a sand-carrying liquid through sand outlet simulation experiment, and checking the washout service life of the sand control screen used in the target oil well in the sand control screen washout service life prediction chart.