CsCl is the most commonly used nucleating agent for preparing chalcogenide glass-ceramics. In this paper, different content of CsCl was added to Ge20Sb10Se65Te5 glass, and glass samples were prepared by different cooling methods. The effect of CsCl on the structure and properties of Ge20Sb10Se65Te5 glass was studied by X-ray diffraction, infrared transmission spectra, differential scanning calorimetry, thermal expansion and Raman spectra. The results show that (100-x)Ge20Sb10Se65Te5-xCsCl(x%=0%， 1%， 2%， 3%， 4%， mass fraction) glass prepared by salt bath cooling has a typical amorphous structure and good infrared transmittance. After adding CsCl into Ge20Sb10Se65Te5 glass, the long-wave cut-off wavelength of the glass has no obvious change, but the average linear expansion coefficient increases obviously. With the increase of CsCl content, the density, micro Vickers hardness, initial crystallization temperature, crystallization peak temperature, yield point and softening point of the glass gradually decrease, and the thermal stability of the glass decreases. With the increase of CsCl content, the content of Sb—Se bond in glass decreases, and the packing degree of the glass structure decreases, which is also the reason for the decrease of the glass density and micro Vickers hardness.