A compound represented by formula, a stereoisomer thereof or a pharmaceutically acceptable salt thereof, wherein, E is selected from -N(R 5)-, -O- and -C(R 6)(R 7)-; R 1 is selected from C 1-3 alkyl, C 1-3 alkoxy and C 3-6 cycloalkyl, wherein the C 1-3 alkyl, C 1-3 alkoxy and C 3-6 cycloalkyl are optionally substituted with 1, 2 or 3 Ra; R 2 is selected from H, F, Cl, Br, I, OH and NH 2; R3 is selected from H, F, Cl, Br, I, OH, NH 2, CN, C 1-3 alkyl and C 1-3 alkoxy, wherein the C 1-3 alkyl and C 1-3 alkoxy are optionally substituted with 1, 2 or 3 Rb; R 4 is selected from C 1-6 alkyl and N(R c)(R d); R 5 is selected from H, C 1-6 alkyl, C 3-6 cycloalkyl, C 1-6 alkyl-C=O-, C 1-6 alkyl-O-C=O- and C 3-6 cycloalkyl-C=O-, wherein the C 1-6 alkyl, C 3-6 cycloalkyl, C 1-6 alkyl-C=O-, C 1-6 alkyl-O-C=O- and C 3-6 cycloalkyl-C=O- are optionally substituted with 1, 2 or 3 R e; R 6 and R 7 are each independently selected from H, F, Cl, Br, I, OH, NH 2, CN, C 1-6 alkyl and C 1-6 alkoxy, wherein the C 1-6 alkyl or C 1-6 alkoxy are optionally substituted with 1, 2 or 3 R f; L 1 is selected from a single bond, -(CH 2) m - and -(CH 2) m -O-; m is selected from 1, 2, 3 and 4; ring B is selected from phenyl and 5- to 6-membered heteroaryl, wherein the phenyl and 5- to 6-membered heteroaryl are optionally substituted with 1, 2 or 3 R g; Ra and Rb are each independently selected from F, Cl, Br, I, OH and NH 2; R c and Rd are each independently selected from H, C 1-3 alkyl and C 3-6 cycloalkyl, wherein the C 1-3 alkyl and C 3-6 cycloalkyl are each independently selected from 1, 2 or 3 R; or, R c and Rd together with the N atom to which they are attached form 4- to 6-membered heterocycloalkyl optionally substituted by 1, 2 or 3 R; R e, R f and R g are each independently selected from F, Cl, Br, I, OH and NH 2; each R is independently selected from F, Cl, Br, I, OH and NH 2; and the 5- to 6-membered heteroaryl and 4- to 6-membered heterocycloalkyl are each independently comprise 1, 2, 3 or 4 heteroatoms or heteroatom groups independently selected from -NH-, -O-, -S- and N. E is selected from -N(R 5)-, -O- and -C(R 6)(R 7)-; R 1 is selected from C 1-3 alkyl, C 1-3 alkoxy and C 3-6 cycloalkyl, wherein the C 1-3 alkyl, C 1-3 alkoxy and C 3-6 cycloalkyl are optionally substituted with 1, 2 or 3 Ra; R 2 is selected from H, F, Cl, Br, I, OH and NH 2; R3 is selected from H, F, Cl, Br, I, OH, NH 2, CN, C 1-3 alkyl and C 1-3 alkoxy, wherein the C 1-3 alkyl and C 1-3 alkoxy are optionally substituted with 1, 2 or 3 Rb; R 4 is selected from C 1-6 alkyl and N(R c)(R d); R 5 is selected from H, C 1-6 alkyl, C 3-6 cycloalkyl, C 1-6 alkyl-C=O-, C 1-6 alkyl-O-C=O- and C 3-6 cycloalkyl-C=O-, wherein the C 1-6 alkyl, C 3-6 cycloalkyl, C 1-6 alkyl-C=O-, C 1-6 alkyl-O-C=O- and C 3-6 cycloalkyl-C=O- are optionally substituted with 1, 2 or 3 R e; R 6 and R 7 are each independently selected from H, F, Cl, Br, I, OH, NH 2, CN, C 1-6 alkyl and C 1-6 alkoxy, wherein the C 1-6 alkyl or C 1-6 alkoxy are optionally substituted with 1, 2 or 3 R f; L 1 is selected from a single bond, -(CH 2) m - and -(CH 2) m -O-; m is selected from 1, 2, 3 and 4; ring B is selected from phenyl and 5- to 6-membered heteroaryl, wherein the phenyl and 5- to 6-membered heteroaryl are optionally substituted with 1, 2 or 3 R g; Ra and Rb are each independently selected from F, Cl, Br, I, OH and NH 2; R c and Rd are each independently selected from H, C 1-3 alkyl and C 3-6 cycloalkyl, wherein the C 1-3 alkyl and C 3-6 cycloalkyl are each independently selected from 1, 2 or 3 R; or, R c and Rd together with the N atom to which they are attached form 4- to 6-membered heterocycloalkyl optionally substituted by 1, 2 or 3 R; R e, R f and R g are each independently selected from F, Cl, Br, I, OH and NH 2; each R is independently selected from F, Cl, Br, I, OH and NH 2; and the 5- to 6-membered heteroaryl and 4- to 6-membered heterocycloalkyl are each independently comprise 1, 2, 3 or 4 heteroatoms or heteroatom groups independently selected from -NH-, -O-, -S- and N.