This study investigates the structural dynamic behavior of a heat exchanger. We employ a direct algorithm to obtain computational modal parameters and the Polymax method for experimental modal extraction. The Modal Assurance Criterion (MAC) is applied to quantify the correlation between simulated and tested modal shapes. Results demonstrate improved model accuracy for industrial thermal systems. This study conducts a sensitivity analysis of measurement point MAC values to improve modal parameter identification accuracy and testing efficiency. Structural optimization techniques are implemented to refine the finite element model parameters of the heat exchanger, thereby enhancing model accuracy. The study demonstrates that the validation of modal parameter identification and finite element model correction methods improves the accuracy of heat exchanger finite element models. These methods provide a reference for modal parameter identification and model correction in similar structures. Additionally, they establish a theoretical foundation for structural dynamic analysis and optimal design of heat exchanger.