Abstract: Rotor deflection is an important aspect of turbine calculations, and the deflection curve serves as a basis for clearance adjustments during rotor alignment. In this study, a computational model of the turbine rotor was established, and the segment integration method was used to systematically analyze and calculate the distributions of support reactions, bending moments, and deflections. A graphical user interface program was then developed using the C# language to enable fast and accurate solutions of the theoretical calculations. An equal cross-section rotor was selected to verify the program, and the results showed that the error between the calculated and theoretical values was less than 0.2%. Furthermore, an actual rotor case was analyzed, and the program results were compared with finite element simulation results, with the error controlled within 4.5%, verifying the accuracy and practicality of the developed program.