The present disclosure relates to an oxidation-resistant heat-resistant alloy and a preparing method, which belongs to the technical field of alloys, and solves the problems of the conventional alloys that the oxygen, sulfur and nitrogen contents are high, the proportion of Al 2 O 3 film in the oxidation film at the surface of the alloy is low, and when the aluminum content is high, the toughness of the alloy is poor. The oxidation-resistant heat-resistant alloy of the present disclosure, by mass percentage, comprises: 2.5%-6% of Al, 24%-30% of Cr, 0.3%-0.55% of C, 30%-50% of Ni, 2%-8% of W, 0.01%-0.2% of Ti, 0.01%-0.2% of Zr, 0.01%-0.4% of Hf, 0.01%-0.2% of Y, 0.01%-0.2% of V, N