To address the challenge of winter construction caused by the tendency of industrial diluent C12-14 alkyl glycidyl ether (XY748, freezing point ~4 °C) to solidify at low temperatures, ethylene glycol butyl ether (2-BE) and epichlorohydrin (ECH) were used as raw materials to synthesize a butyloxyethyl glycidyl ether (DGYM) with an ultra-low freezing point (DSC measurement < -110 °C) and low odor via a two-step process. The modifying effect of DGYM on bisphenol A-type epoxy resin (DGEBA) was investigated and compared with XY748. The modification effect on bisphenol A epoxy resin (DGEBA) was investigated by viscometer, universal testing machine, DSC, SEM, and TGA, and compared with XY748. Results indicate that 10wt.% DGYM reduces the viscosity of the DGEBA system by 92.01% (to 934.4 mPa·s), significantly outperforming the XY748-modified system at the same addition level (2095 mPa·s). The tensile strength of DGYM-modified cured material reaches 60.66 MPa, with flexural strength and elongation at break increasing by 95.34% and 31.17%, respectively, exhibiting ductile fracture characteristics. TGA confirms no significant impairment to thermal stability, while DSC measurements of Tg demonstrate excellent heat resistance. Furthermore, adhesives prepared with DGYM exhibit superior bonding performance and a simplified production process.