Abstract: Based on the traditional collapse mechanism, technical characteristics of Baosteel anti-collapse casing series were introduced, highlighting on alloying design, texture distribution, high strength-toughness mechanisms and casing string design. The collapse resistance mechanisms were researched from the points of grain refining, precipitation strengthening, and texture optimizing. Three-stage corrosion behavior of the casing series in H₂S saturated aqueous brine solutions was proposed. A prediction model of collapse strength was finally constructed for the casing series.