The invention discloses a die and method for bonding a friction material for a conical surface of an intermediate ring of a synchronizer. The bonding die is mainly composed of an upper die body, a lower die body and a heating mechanism, wherein the upper die body is provided with a floating assembly, and the lower die body is provided with a material ejection assembly. By means of the bonding die,pressurized and heated bonding of the conical surface, with the friction material attached in advance, of the intermediate ring of the synchronizer can be achieved, and automatic discharging and material ejection can be achieved after bonding is completed; uniformity of the heating effect is guaranteed; bonding efficiency is improved; the adhesion influence of the contact parts of the intermediate ring and the upper die body as well as the contact parts of the intermediate ring and the lower die body is avoided; and bonding quality and production efficiency are improved.