Disclosed are a Bruton's
tyrosine kinase and a
mutant degrader thereof, or a stereoisomer thereof, or a stereoisomer mixture thereof or a pharmaceutically acceptable salt thereof, and an application thereof in the preparation of a
drug for treating diseases, disorders or conditions that would benefit from the degradation of the Bruton's
tyrosine kinase and the
mutant thereof. The compound of the present invention can degrade BTK
protein, can degrade BTKC481S
protein, has an anti-proliferation inhibiting effect on tumor
cell strains Mino and OCI-LY10, shows good anti-tumor activity in an OCI-LY10 subcutaneous
transplantation tumor model, has an inhibiting effect on
B cell activation, and can be applied to
B cell or
plasma cell proliferative diseases and autoimmune diseases. The compound of the present invention has good oral absorption properties, and can be applied to
oral treatment of human or animal
B cell or
plasma cell proliferative diseases and autoimmune diseases.