Abstract: The evaluation of mechanical performance of reactor pressure vessel (RPV) steel is the main content of the life extension evaluation of nuclear power plants, and the increase of ductile-brittle transition temperature caused by irradiation damage is the main factor affecting operational safety and life. The toughness and brittleness transition evaluation of RPV steel is carried out by drawing surveillance samples, but the shortage of the surveillance samples forces material workers to study the toughness evaluation using small sample and sample reconstitution technique. The toughness evaluation methods of RPV steel at home and abroad in recent years are discussed, and the application of several nondestructive testing techniques on RPV steel mechanical property testing is described. The research progress on the irradiated embrittlement mechanism of RPV steels, especially the microstructure evolution mechanism of RPV steel under the high irradiation condition, in the past three years at home and abroad is described. Finally, the prospect of toughness evaluation and related mechanism research of RPV steel in China is presented.