Metal powder core flux-cored wire for welding fire-resistant and weather-resistant steel

The invention provides a metal powder core flux-cored wire for welding fire-resistant and weather-resistant steel. The metal powder core flux-cored wire is composed of a steel belt and a metal powder flux core, and the metal powder flux core is prepared from the following components in percentage by mass: 0.70-0.95% of graphite, 5.5-8.5% of electrolytic manganese, 5.5-8.5% of 45 # ferrosilicon, 5.0-8.0% of nickel powder, 1.0-5.0% of molybdenum powder, 1.0-3.0% of copper powder, 0.35-0.85% of ferrovanadium, 0.1 to 0.5% of ferrotitanium, 0.5 to 3.0% of chromium metal and the balance of reduced iron powder; and the sum of the mass fractions of the components is 100%. The metal powder core flux-cored wire for welding the fire-resistant and weather-resistant steel can be used in cooperation with Q460 fire-resistant and weather-resistant steel welding, the high-temperature yield strength reaches 2/3 or above of the normal-temperature yield strength specified value of a Q460 Mpa steel plate, and the metal powder cor