Through different post-weld heat treatment tests,the effects of different holding time on the properties and microstructure of CHE558HRF deposited metal for nuclear power welding rods were investigated. The results showed that with the increase of post-weld heat treatment time,the tensile strength changed little and the impact energy was significantly improved. Through metallographic structure and electron microscopy analysis,the microstructure of the weld center gradually changed to acicular ferrite with the increase of heat treatment time,and the M-A component attached to the massive ferrite gradually disappeared.