Abstract: Solidification path of Al-4Cu-6Si alloy was calculated based on two different thermodynamic data-acquisition methods: direct coupling with Thermo-Calc and calling regression functions. In order to verify the correctness of the above two kinds of methods, a parallel experimental investigation on Al-15.05Cu-6.17Si alloy was carried out to compare with calculation results. The results show that the solidification path of Al-4Cu-6Si alloy was L+α→L+α+Si→L+α+θ+Si. The volume fraction of primary phase, binary eutectic and ternary eutectic calculated by coupling with Thermo-Calc method were 50.813%, 37.234%, 11.953%, respectively, and the calculation results got by calling regression functions method were 50.809%, 38.000%, 11.191%. Comparing the calculation results from the two kinds of thermodynamic data-acquisition methods, it was found that the accuracy of the two methods was relatively close, but calling regression function method was much more efficient than coupling with Thermo-Calc method. The time of calling regression function method was 1.21% of coupling with Thermo-Calc method. The correctness for calculating solidification path through two different thermodynamic data-acquisition methods was demonstrated by using solidification experiment of Al-15.05Cu-6.17Si alloy.