The invention relates to dispersed precipitated phase strengthened austenitic stainless steel with high Cr and high Ni and a thermal processing method. The stainless steel component comprises the components in percentage by weight as follows: 0.2-0.8% of Si, not greater than 2% of Mn, 20-28% of Cr, 16-25% of Ni, not greater than 3% of Mo, 0-1% of Ti, 0-1% of W, 0-1% of Zr, 0-1% of V and the balance of Fe. The method comprises the following steps of: weighing according to the component proportion, refining and moulding; thermally forging, wherein the thermal rolling process is that rolling in four gates at 1180-1230 DEG C with the final rolling temperature over 1030 DEG C, wherein deformation is not less than 40% every time, and quenching and cooling; insulating for 20min to 1 hour at 1120-1200 DEG C; immediately quenching; performing high temperature annealing treatment at 950-1050 DEG C, insulating for 1.5-4 hours, then, furnace cooling or air cooling to room temperature, and directly quenching and quickly cooling. According to the invention, MC phase is separated out in the high temperature deformation process by comprehensively adding Ti, W, V, Zr and C elements. After thermal forming, relative materials are separated out through fine dispersion. Dimension of a second precipitated phase is controlled by the cooling rate through controlling subsequent thermal deformation processing parameters and the thermal treatment system.