Abstract: Based on finite element analysis and the principle of mechanical equivalence, the supporting structures for the hydrogen and oxygen turbine pumps of a rocket engine were analyzed. By the principle of mechanical equivalence, a complex temperature model of FEM for which boundary conditions are difficult to be confirmed is transformed to a simple friction FE model. The complex inner structures of the rocket engine are simulated using the simple beam element, and the possible error is studied. Applying a mechanical equivalent model, the highly stressed region in the hydrogen turbine pump's body is analysed. Finally, mechanical equivalent analysis on the hydrogen turbine pump's body indicates the deficiency in its structural design.