This article aims to improve the structural design of the packaging foam of a commercial duct type air conditioner so that an optimized solution for both the energy-absorbing performance under drop test and economical advantages through weight reduction can be realized. Such optimized foam structure is obtained by analyzing a series of simulation results utilizing both LS-DYNA® and OptiStruct® and further verified under drop test. The major approach is as follows:firstly, the dynamic responses of the foam are extracted from all the testing conditions under simulation; secondly, the dynamic responses are converted to the equivalent stress state using inertial release method and utilized by the topology optimization method offered by OptiStruct®; lastly, the new foam is designed, fully assembled, tested and verified under drop test. Through our systematic approach, in comparison to the original design, a 30% weight reduction of the foam can be attained. The complete package with assembled foam and product not only passed the drop test but also achieved an overall reduced peak acceleration. In addition, simulation results are consistent with experimental results with over 90% accuracy for the acceleration curve and very similar region for the failed foam. In conclusion, through structural topology optimization method, the packaging cost can be reduced while ensuring the survivability of the product under drop test.