The invention provides a phenolic resin / phosphate hybrid adhesive and a preparation method thereof, relating to an adhesive and a preparation method thereof. The invention solves the problems of low working temperature, rigorous curing process and low adhesion strength of the conventional high-temperature resisting phenolic resin adhesive. The adhesive is prepared from phenolic resin, heat-resistant reinforced resin, a coupling agent, a toughening agent, phosphate, a curing agent, a framework material, fillers and a dispersing agent. The preparation method comprises the following steps of: mixing the phenolic resin, the heat-resistant reinforced resin, the coupling agent and the toughening agent and then evenly stirring to obtain a phenolic resin component; then mixing the phosphate, the curing agent, the framework material and the fillers and then evenly stirring to obtain a phosphate component; and then adding the phosphate component and the dispersing agent into the phenolic resin component and evenly stirring. The adhesive can be applied in aerospace, military and machining industries with the working temperature above 800 DEG C.