The invention belongs to biological and medical fields and the field of cancer therapy, and discloses an application of B7x as a glioma immunotherapy target. The invention provides an application of the B7x in preparing an anti-glioma medicine, and the B7x is a family member of a co-simulating molecule B7. The invention also provides a kit for detecting the B7x and an application of the kit. The B7x can be used as a drug target and a diagnostic marker for glioma. By virtue of the target, the targeted therapy of the glioma can be effectively achieved, a curative effect can be improved, and meanwhile toxic and side effects can be reduced.