The present invention provides a compound having tyrosine protein kinase JAK1- or JAK2-inhibittion and degradation activity. Specifically, the present invention provides a compound as represented by the following formula I, wherein the definition of each group is as stated in the description. The compound provided by the present invention has excellent JAK1- or JAK2-inhibittion and degradation activity, and can be used for preparing drugs for treatment of JAK1- or JAK2-related diseases.