Pyrrole pyrimidine five-membered nitrogen-heterocyclic derivative and application thereof

The invention relates to a novel JAK (Janus kinase) inhibitor, namely a pyrrole pyrimidine five-membered nitrogen-heterocyclic derivative, and application of the pyrrole pyrimidine five-membered nitrogen-heterocyclic derivative in preparation of a medicine for preventing and/or treating JAK function-related adaptation diseases. The pyrrole pyrimidine five-membered nitrogen-heterocyclic derivative disclosed by the invention is an ideal efficient JAK inhibitor, and can be used for treating or preventing diseases such as rheumatoid arthritis, polycythemia vera, psoriasis, primary thrombocythemia and myelofibrosis.