The invention provides a technological method for improving the high temperature creep resistant property of heat-resistant 403Nb blade steel, and belongs to the technical field of metallurgy materials. The method comprises the following steps that 1, the heat-resistant 403Nb blade steel is subjected to temperature homogenization according to two-stage heating; 2, primary thermal deformation treatment is conducted; 3, secondary thermal deformation treatment is conducted; 4, tempering treatment is conducted. According to the technological method for improving the high temperature creep resistant property of the heat-resistant 403Nb blade steel, on the basis that chemical components of existing heat-resistant 403Nb blade steel are not changed, a change of the structure state is achieved only through minor adjustment of the production technology, the purpose of improving the high-temperature mechanical property is achieved, and particularly, the high temperature creep resistant property is greatly improved; shapes of processing materials or finished products are not limited, no special requirement on applied forming methods exists, and the processing methods such as rolling, extruding and forging for bars, boards, pipes and the like can be implemented according to the technological method.