The invention discloses a method for calculating the amount of crushed stones in the crushed stone seal layer, each crushed stone in the crushed stone seal layer is approximately regarded as a sphere (the diameter of the sphere is taken as the median value d of the particle size range of the crushed stones, and the radius r =2 / d, unit cm), according to the gravel's own density ρ (g / cm 3 ), the mass m(g) of a single crushed stone can be approximated; 2 ) plane, according to the maximum cross-sectional area S′ of the approximate sphere, the total number N of spheres required to cover a unit area can be calculated; since the crushed stones in physical engineering are not regular spheres, and the crushed stones are in contact with the crushed stones There is a certain gap between each other, so the calculated mass m of a single gravel and the total number N of spheres required to cover a unit area need to be corrected, and the correction coefficients are K 1 、K 2 ; Then calculate the consumption of gravel in the gravel seal according to the following formula: M=10.5K 1 K 2 ρr, where M is the paving unit area (1m 2 ) the mass of gravel required, in kg. The invention effectively solves the problem of determining the amount of crushed stones in the crushed stone seal layer, and can perform accurate quantitative calculations for crushed stones with different particle sizes, thus avoiding determination through tedious tests, and the calculation is simple.