A small molecule antagonist compound having a toll-like receptor 3/7/8/9 inhibitory function and its use in inhibiting TLR7, TLR8, TLR9 and TLR3 are disclosed. A novel compound expressed by TAC5 and TAC5-a, TAC5-c, TAC5-d or TAC5-e which are derivatives thereof not only prevents TNFα secretion, NFkB activation, IkB degradation and MAPKs phosphorylation induced by poly(I:C) (TLR3 agonist), IMQ (TLR7 agonist), CL075 (TLR7/8 agonist), R848 (TLR7/8 agonist), TL8 (TLR8 agonist) or CpG ODN (TLR9 agonist), but also inhibits generation of inflammatory cytokine, and thus is highly advantageous for preventive or therapeutic use for TLR3/7/8/9-related autoimmune diseases and inflammatory diseases including systemic lupus erythematosus, psoriasis and the like.