The invention relates to a high-strength high-toughness anticorrosion high-temperature bearing / pinion steel and a preparation method thereof, belonging to the technical field of bearing / pinion steel. The bearing / pinion steel comprises the following chemical elements in percentage by weight: 0.10-0.22% of C, at most 0.5% of Mn, at most 0.5% of Si, 12.0-15.0% of Cr, 1.50-3.00% of Ni, 4.00-6.00% of Mo, 0.50-0.90% of V, 12.0-15.0% of Co, 0.30-2.00% of W, 0.02-0.08% of Nb and the balance of Fe and inevitable impurities, wherein the V / Nb ratio is 25-35, the Mo / W ratio is 6-12, the Co / Mo ratio is 2-3, Cr+6Si+4Mo+1.5W+11V+5Nb<=52%, 40C+2Mn+4Ni+30N+2Co>=42%, and [O]+[N]+[H]<=0.0040%. The preparation method comprises the following steps: proportioning and controlling the components; carrying out vacuum smelting; carrying out hot working on a steel ingot to obtain a steel product; carrying out surface carburized hardening treatment on the steel product; and carrying out heat treatment on the steel product. The invention can satisfy the requirements of new-generation bearing / pinion steel for bearing the actions of high temperature and corrosive environment in the service process, and implements good cooperation of high strength, high hardness, high toughness, high temperature properties and anticorrosion property.