Abstract: Using casings for well-drilling is regarded as an advanced well-drilling technology. Since casings are substituted for drill pipes,and thus directly jointed with the drilling tool assembly in the well so as to get the well-drilling operation conducted together with the down-well operation of casings. Drilling well with casings features such advantages as shortening operation time,minimizing in-well accident rate,improving the hydrocharacteristics and reducing operation costs,etc. Addressing the fact that casings are worn with different severities during the drilling process,anti-collapse test research is carried out on the Baosteel-made Ф139.7 mm×7.72 mm P110 casing for well-drilling service by means of simulating the even wear and uneven wear operation conditions of casings and the test method with the full-sized casing sample. The research result is instructive to a certain extent for choosing proper casings for well drilling purpose.