Abstract: Objective The aim is to explore evolution law of microstructure and reliability of mechanical properties of ferrite-elconite brazed joints under different liquid nitrogen shock cycles. Methods Ferrite and tungsten-copper were subjected to surface metallization treatment by magnetron sputtering process, and connection of the two was achieved through vacuum brazing. Brazed joints were subjected to 0～60 cycles of liquid nitrogen shock treatment. Through microstructure observation and shear strength testing, microstructure morphology evolution and attenuation law of mechanical properties of brazed joints were analyzed. Results Research findings indicate that after 30 cycles of liquid nitrogen shock, microstructure and mechanical properties of brazed joints shows no significant changes with shear strength maintaining above 20 MPa. However, after 60 cycles of liquid nitrogen shock, some Cu-Sn intermetallic compounds in brazed joints transforms from scallop-like to needle-like morphology, resulting in a decrease of joint strength to approximately 16 MPa. Conclusion Ferrite-elconite brazed joints demonstrate good stability of microstructure and mechanical properties after liquid nitrogen shock, and the mechanical properties meet engineering requirements for high-order mode absorber in synchrotron radiation light sources.