In order to explore the law of Cl^- affecting the low-temperature reduction disintegration property of vanadium titanium sinter, a systematic quantitative research on the mineral composition and microstructure of the sinter before and after spraying CaCl₂ from the perspectives of process mineralography and by means of optical microscope and scanning electron microscope. The results show that no significant difference is found out in the mineral-phase structure before and after on-site spraying CaCl₂. But after 500 ℃ reduction, a significant difference is found out in the mineral phase structure and low temperature reduction disintegration rate of sinter before and after spraying CaCl₂. The quality score of calcium ferrite in sinter after reduction without spraying CaCl₂ is very low, but the sinter spraying CaCl₂ after reduction still holds its alternative titanomagnetite bonded by acicular and columnar calcium ferrite, which low temperature reduction disintegration index (RDI_+3.15mm) is significantly increased. It is known that, according to SEM-EDS analysis, CaCl₂ mainly shows crystal particles adsorbed on the surface of sinter pores or mineral particles without significant difference between CaCl₂ crystals before and after reduction, and without obvious chemical reaction between CaCl₂ and sinter. It is found out, according to field investigation, that the presence of CaCl₂ in sinter can corrode furnace top equipment, clog the gas pipeline, and reduce the service life and furnace processor of furnace top equipment. Therefore, how to improve the low temperature reduction disintegration property to increase the quality of sinter through other means or by seeking alternatives is still a problem to be solved for the blast furnace production.