The invention discloses a bonding resin for the interface of polyethylene and glass fiber and a preparation method thereof, belonging to the field of high-polymer materials. The bonding resin comprises the following raw materials by weight: on the basis of the total weight of the raw materials, 71 to 95% ofpolyethylene, 0.5 to 1.0% of an initiator, 0.5 to 1.0% of an auxiliary agent, 3.0 to 25%of acidic monomers, 0.5 to 1.0% of an oxidizing agent and 0.5 to 1.0% of a reducing agent. The bonding resin disclosed by the invention has the beneficial effects that the bonding resin has high peeling strength when applied to the polyethylene/glass fiber interface, allows the bonding interface of polyethylene and glass fiber to have interlaminar shear strength of more than 10 MPa, can resist multiple hot-and-cold impact brought by water with a temperature of 100 DEG C to 0 DEG C and meets the demands of water treatment containers; and the preparation method for the bonding resin is simple in process, easy in processing and convenient to implement.