The present invention provides a series of Janus kinase inhibitors, specifically a chemical structure as shown in the following formula (I) or pharmaceutically acceptable salts thereof and their applications of preparation of the drugs of treatment of JAK-associated diseases.本發明公開了一系列Janus激酶抑制劑,具體公開了式(Ⅰ)化合物或其藥學上可接受的鹽及其在製備治療與JAK相關疾病的藥物中的應用。