FIELD: chemistry.SUBSTANCE: invention relates to a novel dihydropyrimidinium compound of formula (I) or a pharmaceutically acceptable salt thereof. In formula (I)(I)0–2 of D11–14 separately and independently selected from a single bond, -C(=O)N(Rd3)-, -N(Rd4)-, -S(=O)2N(Rd6) -, -S(=O)N(Rd7)-, -O-, -S-, -C(=O)O-, -C(=O) - or -S(=O)2-, and the rest are selected from -C(Rd1)(Rd2)-； L is selected from a single bond, -S-, -NH-, -S(=O)-, -S(=O)2-, -N(Rd4)-, -[C(Rd1)(Rd2(I)]0–6； R2 is selected from；D21 is selected from a single bond, -N(Rd4)-, -O-, where Rd4 is hydrogen； R21 is independently selected from H, C1–4alkyl, which is optionally substituted with R01, wherein each of R01 is independently selected from F, Cl, Br, I, C1–10alkyl； R3 separately and independently selected from following groups, optionally substituted with R01:6–10-membered aromatic ring group or 5–6-member heteroaromatic ring group containing a sulphur atom or a nitrogen atom as a heteroatom, wherein each of R01 is independently selected from F, Cl, Br, I, C1–10alkyl； R4 separately and independently selected from following groups, optionally substituted with R01: C1–10alkyl or 5–6-member heteroaromatic ring group containing nitrogen and sulphur atoms or a nitrogen atom as a heteroatom, wherein each of R01 is independently selected from F, Cl, Br, I, C1-10alkyl； R3' is selected from H, C1-4alkyl； Rd3 and Rd6–7 separately and independently selected from H, CN, C1-4alkyl, benzyl optionally substituted with C1-10alkoxy； Rd4 is selected from H, C1-4alkyl, CN, or selected from the following groups, optionally substituted with R01: -C(=O)O-C1–4alkyl, -S(=O)2NH-C1–4alkyl, -C(=O)-C1–4alkyl, -S(=O)2-C1–4alkyl, -C(=O)NH-C1–4alkyl, 3–6-member heterocyclylcarbonyl, where heterocyclyl has oxygen as a heteroatom, -C(=O)-C3–6cycloalkyl, C1–4alkyl-5–6-member heteroaryl with 1–2 heteroatoms selected from nitrogen or oxygen or nitrogen and oxygen, -S(=O)2-C3–6cycloalkyl, -C1–4alkyl-C(=O)NH2, -C1–4alkylphenyl, -C1–4alkyl-
