Abstract: The MUF resin modified with polyethylene glycol with a molecular weight of 4 000 and effects of the amount of polyethylene glycol on the adhesion properties, cold boiling water stripping and toughness of MUF was studied in this paper. The results showed that the introduction of polyethylene glycol greatly improved the strength and toughness of MUF resin. When the amount was less than 8%, polyethylene glycol had both strengthening and toughening effect on MUF resin. At 8% or more, the effect of strengthening on MUF was not obvious, but the effect of toughening on MUF was remarkable. When the addition amount was 2%−8%, polyethylene glycol had a great improvement on the bonding performance, water resistance and bonding stability of MUF resin. The controlled MUF resin had a brittle fracture mode, but MUF resin with polyethylene glycol had a fracture mode of ductile fracture.