The present invention relates to a selective Bruton's tyrosine kinase (BTK) inhibitor compound, a pharmaceutical composition, preparation and use thereof in preparation of a drug. The compound of the present invention has a structure of Formula II or Formula II′: or their optical isomers, or pharmaceutically acceptable salts or solvates; where each Rg is independently H, halogen, —CF2H, —CF3, —CN, C1-C3 alkyl, or C1-C3 alkoxy; n is selected from 0, 1 and 2; Rd is selected from Re is selected from H, CH3, C2-C6 alkyl, C1-C6 azaalkyl, and C1-C6 oxaalkyl, wherein CH3, C2-C6 alkyl, C1-C6 azaalkyl and C1-C6 oxaalkyl are further substituted with amino, hydroxyl, and C1-C3 alkyl; Y1, Y2, Y3 and Y4 are independently selected from C(Rf) and N, and at least one of Y1, Y2, Y3 and Y4 is N, wherein Rf is selected from H, halogen, C1-C3 alkyl, —CF3, and —CF2H.