In order to solve the problem of short pot life to surface curing of silicate adhesives into film when exposed in air, the adhesives were modified by adding polyethylene glycol (PEG) to silicate adhesives, and the pot life, rheological performance, microscopic morphology, molecular structure, thermal stability and adhesive performance were systematically studied by using rheometer, scanning electron microscope, infrared spectrometer, thermogravimetric infrared mass spectrometer and universal tensile machine. The results show that when the PEG dosage in silicate adhesives is 6% (mass fraction), the pot life is extended to 50 min. The PEG is uniformly distributed inside adhesive, which significantly enhances the densification and thixotropy. The pre-curing activation energy calculated by Arrhenius equation increases from 8.47 kJ/mol to 12.61 kJ/mol. PEG does not affect the bonding performance of system and has a good extension effect on the pot life of same types of silicate adhesives.