Nitrogen-containing fused heterocycle compound as well as preparation method, composition and application thereof

The invention discloses a nitrogen-containing fused heterocycle compound shown by a formula I, a pharmaceutically acceptable salt thereof, or enantiomers, diastereoisomers, tautomers, solvates, metabolic precursors or prodrugs of the nitrogen-containing fused heterocycle compound and the pharmaceutically acceptable salt thereof, or a pharmaceutical composition containing the nitrogen-containing fused heterocycle compound and an application of the nitrogen-containing fused heterocycle compound. The nitrogen-containing fused heterocycle compound disclosed by the invention has relatively good antitumor activity.