Abstract: The 32Cr13Mo steel used for the sensor elasticity was subjected to cryogenic treatment. The material was analyzed using X-ray diffractometer, optical microscope, scanning electron microscope, electronic universal testing machine, thermal expansion instrument, and the effects of different cryogenic treatment times on the microstructure, mechanical properties, and thermal expansion properties of the material were studied. The results show that cryogenic treatment could refine the lath martensite, promoted partial of martensite to austenite transformation, and promoted carbide precipitation. With the extension of cryogenic treatment time, the tensile strength of 32Cr13Mo steel showed a decreasing trend, and the elongation at break first increased and then decreased. After 12 of cryogenic treatment, the elongation at break of the sample was the highest, at 21%, which was 25.5% higher than that of the sample without cryogenic treatment. With the extension of cryogenic treatment time, the impact toughness of the material showed a trend of first increased and then decreased. After 12 h of cryogenic treatment, the impact toughness of the sample was the highest, at 241.5 kJ/m², which was 20.7% higher than that of the sample without cryogenic treatment. After 36 h of cryogenic treatment, the average thermal expansion coefficient of the material was the smallest.