The invention discloses a thermal treatment method for an ultralow-temperature high-strength steel for a compressor. An existing thermal treatment process for 25Cr2Ni3Mo steel improves a normalizing temperature, a quenching temperature, quenching times, a cooling medium, tempering times and a cooling medium on the basis of normalizing, quenching and tempering, and adds quenching times, tempering times and cryogenic treatment. The 25Cr2Ni3Mo steel material treated by the thermal treatment method can improve tensile strength and yield strength by 5%, improves plasticity by 10%, can improve low-temperature impact toughness by 30% or more, and can meet requirements, on strength, plasticity, especially impact toughness of ultralow-temperature high-strength steel, in a centrifugal compressor forstandard API617 petroleum, chemistry and gas industry.