A 7-substituted pyrrolo[2,1-f][1,2,4]triazine compound represented by a general formula I or a pharmaceutically acceptable salt thereof: wherein, R 1 is halogen, or C 1-6 alkyl or C 3-8 cycloalkyl which is unsubstituted or substituted with at least one substituent, wherein the substituent is halogen; R 2 is: -C R 5 R 6; -COC 1-6 alkyl; -CN; or, unsubstituted or at least one substituent substituted C 1-6 alkyl, -CH 2 NH-C 1-6 alkyl, -CH 2 N(C 1-6 alkyl) (C 1-6 alkyl), -CH 2 -(saturated heterocyclyl containing 1 to 2 heteroatoms and 3 to 6 carbon atoms), -CH 2 -(saturated heterocyclyl containing 1 to 2 heteroatoms and 3 to 6 carbon atoms)-(saturated heterocyclyl containing 1 to 2 heteroatoms and 3 to 6 carbon atoms), -CH 2 -(saturated spirocyclic group containing 1 to 2 heteroatoms and 4 to 12 carbon atoms), -CH 2 -(saturated bridged ring group containing 1 to 2 heteroatoms and 3 to 12 carbon atoms)-(saturated heterocyclyl containing 1 to 2 heteroatoms and 3 to 6 carbon atoms), or -CH 2 -(saturated bridged ring group containing 1 to 2 heteroatoms and 3 to 12 carbon atoms); wherein the substituent is: halogen; -N(C 1-4 alkyl)(C 1-4 alkyl); -O-C 1-4 alkyl; -CN; -COOH; -CHO; -NHS 2 -C 1-4 alkyl; -N(C 1-4 alkyl)C(C 1-4 alkyl)(C 1-4 alkyl)-CONH 2; =O; -OH; -S 2 N(C 1-4 alkyl)(C 1-4 alkyl); -S-C 1-4 alkyl; -S 2 -C 1-4 alkyl; -CO-C 3-6 cycloalkyl; oxetanyl; morpholinyl; C 3-6 cycloalkyl; -C 1-4 alkyl-N(C 1-4 alkyl) (C 1-4 alkyl); C 1-4 alkyl-O-C 1-4 alkyl which is unsubstituted or substituted with at least one methyl; -CONH 2 which is unsubstituted or substituted with at least one methyl; C 1-4 alkyl-CONH 2 which is unsubstituted or substituted with at least one methyl; -COO-C 1-4 alkyl which is unsubstituted or substituted with at least one methyl; -NH 2 which is unsubstituted or substituted with at least one methyl; -NHCO-C 1-4 alkyl which is unsubstituted or substituted with at least one methyl; -CO-C 1-4 alkyl which is unsubstituted or substituted with at least one substituent A, wherein the substituent A is hydroxyl or methyl; or C 1-4 alkyl which is unsubstituted or substituted with at least one substituent B, wherein the substituent B is -NH 2, -OCH 3, -CONH 2, -OH or -CF 3; in R 2, the heteroatom is selected from at least one of N, O and S, R 5 and R 6 are each independently hydrogen or C 1-6 alkyl; R 3 is wherein R 7, R 8, R 9 and R 10 are each independently hydrogen or C 1-6 alkyl which is unsubstituted or substituted with at least one substituent, wherein the substituent is halogen or hydroxyl; R 4 is -NH 2, -NHCONHR 11 or -NHCO 2 R 12, wherein R 11 and R 12 are each independently C 1-6 alkyl, C 3-8 cycloalkyl or phenyl which is unsubstituted or substituted with at least one substituent selected from at least one of halogen and -C OR 13, wherein R 13 is C 1-6 alkyl which is unsubstituted or substituted with at least one substituent, and the substituent in the R 13 is halogen. R 1 is halogen, or C 1-6 alkyl or C 3-8 cycloalkyl which is unsubstituted or substituted with at least one substituent, wherein the substituent is halogen; R 2 is: -C R 5 R 6; -COC 1-6 alkyl; -CN; or, unsubstituted or at least one substituent substituted C 1-6 alkyl, -CH 2 NH-C 1-6 alkyl, -CH 2 N(C 1-6 alkyl) (C 1-6 alkyl), -CH 2 -(saturated heterocyclyl containing 1 to 2 heteroatoms and 3 to 6 carbon atoms), -CH 2 -(saturated heterocyclyl containing 1 to 2 heteroatoms and 3 to 6 carbon atoms)-(saturated heterocyclyl containing 1 to 2 heteroatoms and 3 to 6 carbon atoms), -CH 2 -(saturated spirocyclic group containing 1 to 2 heteroatoms and 4 to 12 carbon atoms), -CH 2 -(saturated bridged ring group containing 1 to 2 heteroatoms and 3 to 12 carbon atoms)-(saturated heterocyclyl containing 1 to 2 heteroatoms and 3 to 6 carbon atoms), or -CH 2 -(saturated bridged ring group containing 1 to 2 heteroatoms and 3 to 12 carbon atoms); wherein the substituent is: halogen; -N(C 1-4 alkyl)(C 1-4 alkyl); -O-C 1-4 alkyl; -CN; -COOH; -CHO; -NHS 2 -C 1-4 alkyl; -N(C 1-4 alkyl)C(C 1-4 alkyl)(C 1-4 alkyl)-CONH 2; =O; -OH; -S 2 N(C 1-4 alkyl)(C 1-4 alkyl); -S-C 1-4 alkyl; -S 2 -C 1-4 alkyl; -CO-C 3-6 cycloalkyl; oxetanyl; morpholinyl; C 3-6 cycloalkyl; -C 1-4 alkyl-N(C 1-4 alkyl) (C 1-4 alkyl); C 1-4 alkyl-O-C 1-4 alkyl which is unsubstituted or substituted with at least one methyl; -CONH 2 which is unsubstituted or substituted with at least one methyl; C 1-4 alkyl-CONH 2 which is unsubstituted or substituted with at least one methyl; -COO-C 1-4 alkyl which is unsubstituted or substituted with at least one methyl; -NH 2 which is unsubstituted or substituted with at least one methyl; -NHCO-C 1-4 alkyl which is unsubstituted or substituted with at least one methyl; -CO-C 1-4 alkyl which is unsubstituted or substituted with at least one substituent A, wherein the substituent A is hydroxyl or methyl; or C 1-4 alkyl which is unsubstituted or substituted with at least one substituent B, wherein the substituent B is -NH 2, -OCH 3, -CONH 2, -OH or -CF 3; in R 2, the heteroatom is selected from at least one of N, O and S, R 5 and R 6 are each independently hydrogen or C 1-6 alkyl; R 3 is wherein R 7, R 8, R 9 and R 10 are each independently hydrogen or C 1-6 alkyl which is unsubstituted or substituted with at least one substituent, wherein the substituent is halogen or hydroxyl; R 4 is -NH 2, -NHCONHR 11 or -NHCO 2 R 12, wherein R 11 and R 12 are each independently C 1-6 alkyl, C 3-8 cycloalkyl or phenyl which is unsubstituted or substituted with at least one substituent selected from at least one of halogen and -C OR 13, wherein R 13 is C 1-6 alkyl which is unsubstituted or substituted with at least one substituent, and the substituent in the R 13 is halogen.