Disclosed are a salt of a fused ring pyrimidine compound, a crystal form thereof and a preparation method therefor and the use thereof. The fused ring pyrimidine compound is N-[7-(4-fluoro-2-methoxyphenyl)-6-methylthieno[3,2-d]pyrimidin-2-yl]-1-(piperidin-4-yl)-1H-pyrazol-4-amine, having a structure as shown in formula 1. The preparation methods in the invention for the salt of the fused ring pyrimidine compound and the crystal form thereof are simple; and the salt of the fused ring pyrimidine compound and the crystal form thereof at least have the characteristics of having a better stability, not easily absorbing moisture, being of a polycrystalline type, having a chemical stability and pharmacokinetics, and having an improved solubility.