The present invention relates to a pyrrolo[2,1-f][1,2,4]triazine compound, an isomer thereof or a pharmaceutically acceptable salt, ester or hydrate thereof, and a preparation method and application thereof. The pyrrolo[2,1-f][1,2,4]triazine compound has a structure expressed in general formula (I). The pyrrolo[2,1-f][1,2,4]triazine compound expressed in general formula (I) can inhibit a phosphatidylinositol-3 kinase (PI3K) signal pathway, thereby being used to prepare medicine for treating phosphatidylinositol-3 kinase related diseases such as cancer.
