The invention discloses an alloy material flange and a forging technology thereof. An alloy blank of the alloy material flange comprises, by weight, 12.7-12.9% of Ni, 25.3-25.5% of Cr, 0.1-0.12% of C, 0.17-0.19% of Si, 0.72-0.79% of Mn, 0.0015-0.0035% of S, 2.25-2.35% of Mo, 3.25-3.45% of Ti, 3-3.25% of Al, 1.25- 1.85% of Cu, 0.015-0.017% of P, 0.9-1.1% of W, 0.018-0.022% of B, 0.9-1.1% of Nb, 0.11-0.13% of rare earth elements and the balance Fe and impurities. The rare earth elements comprise 12-18% of Yb, 6-11% of Er, 19-25% of Dy, 16-26% of Gd, 8-17% of Ce, 13-18% of La and 15-22% of Th. Through raw material chemical analysis, forging temperature and forging ratio control, solid solution treatment after forging, heat treatment and structure hardening treatment after heat treatment, the forge piece can be used under the conditions of high sulphur and phosphorus content and has good mechanical properties. The alloy material has excellent stress corrosion cracking resistance, pitting corrosion resistance and crevice corrosion resistance, has good oxidizing and non-oxidizing hot acid resistance and has stable mechanical properties in a range of a room temperature to a high temperature of 550 DEG C.