Abstract: To address the issues of path omission and inappropriate calculation of transfer rate matrix in the traditional operational transfer path analysis (OTPA), this paper presents an enhancement to the OTPA method, incorporating partial coherence analysis of the multiple coherence function and the Tikhonov regularization-generalized cross validation (GCV) approach. This improved methodology is applied to t the vibration transfer path analysis of the complex packaging system under random vibration. By analysing the re-coherence function based on the partial coherence analysis of the packaging system, a relatively simplified six-input-single-output mode transfer path model is constructed for the packaging system, and the non-major transfer paths are effectively eliminated; The applicability of the truncated singular value decomposition (TSVD) and Tikhonov regularization methods, along with their respective parameter selections, for calculating the vibration transmittance of complex packaging systems is evaluated. The results demonstrate that the Tikhonov regularization-GCV method yields the smallest discrepancy with the measured data. The accuracy of the enhanced OTPA approach was validated through a comparative analysis of its output with the vibration signals of key components obtained from random vibration tests. The enhanced OTPA method quantifies the vibration contributions of individual transfer paths, enabling the identification of primary vibration transmission routes in complex product packaging systems. This provides a crucial reference point for the subsequent precise design of the cushioning packaging.