Based on the yield criterion and constitutive model of taking into account the effects that the components of tension stresses couple with components of torsional stresses for single crystal Nickel-based superalloy，a subroutine to calculating the thermo elastic-plastic stress-strain of single crystal Nickel-based superalloy on ANSYS platform is developed by APDL and UPFs of ANSYS. Numerical simulation of uniaxial tension thermo elastic-plastic stress-strain for single crystal nickel-based superalloy specimens at 680 ℃ is done along different orientations [001]，[011] and [111]，and the calculating results is validated by test data. At last，the three dimensional nonlinear cyclic stress-strain of single crystal turbine disk-blade assembly is analyzed.