The invention provides an adhesive prepared based on amino siloxane, and a preparation and application method thereof. The amino siloxane is subjected to two-step reaction to prepare benzoxazine group-containing siloxane. The method has simple and controllable synthesis conditions and high synthesis efficiency; the benzoxazine group-containing siloxane synthesized by the method can be directly used as the adhesive, and has high bonding strength; the benzoxazine group-containing siloxane synthesized by the method can be also used as a base formula, and serves as the adhesive after other fillersare added so as to meet the different needs of various special occasions.