The present invention relates to a heterocyclic compound, a pharmaceutical composition containing the same, a preparation method thereof, and a use thereof as a fibroblast growth factor receptor (FGFR) inhibitor. The compound is a heterocyclic compound as shown in Formula I, or a pharmaceutically acceptable salt, a prodrug, a solvate, a polymorph, an isomer, or a stable isotopic derivative thereof. The present invention further relates to a method of treating or preventing a FGFR-mediated disease, such as cancer, using the compound.