The invention relates to a welding electrode for Ni steel welding. A heat-resistant steel welding electrode comprises an H08E welding core and a cover, wherein the cover contains the following components by weight percent: 20-30% of marble, 13-30% of fluorite, 3-5% of rutile, 8-12% of iron powder, 1-2% of sodium carbonate, 2-4% of silicon iron, 2-4% of ferromanganese, 5-7% of metallic nickel, 1-3% of ferrotitanium, 1-3% of silica powder, 1-3% of flogopite, 1-2% of zircon sand and 17-21% of pure sodium silicate. According to the invention, after the (620+/-10 DEG C)*1h thermal treatment on the deposited metal, the mechanical property is stable, the strength is suitable, the toughness is better, the production processing property is excellent, the surface of the welding electrode is smooth, the eccentricity is stable, and the yield is high. The electrical arc is stable; the combustion is stable during a welding process; the spreadability and the fusing property are better; the formation of weld is attractive; the dregs-removing property is better.