Based on the equivalent isochronous stressstrain curves, a method for creep calculation in multiple working conditions is presented. The method was applied to calculate the residual deformation of a gas turbine blade in four working conditions（total 150 h）, which was also compared with deformation values obtained by other creep calculation methods and engine 150 h real durability tests. It is known from the comparison with other creep methods and analysis results that the proposed method could have the calculation accuracy and improve the computational efficiency, and this method has better practical value of engineering as well.