Abstract: The construction of underground gas storage (UGS) is a project with high risk and high investment, so its design proposal optimization influences directly its overall economic benefits. Thus, a series of influential factors were analyzed comprehensively, including UGS total cost, cushion gas volume, maximum formation pressure, the number of working wells, compressor power and UGS service life. Then, a UGS design proposal optimization model was established by combing the multiple-objective-decision osculating value method and the entropy weight method together. And finally, a certain UGS in China was taken as an example and its six design proposals were analyzed for optimization. It is shown that the fourth UGS design proposal is the optimal one whose optimization result is less deviated from that of the related reference, for its weight on UGS total construction cost is increased. And this practice is in accordance with the requirement that large underground engineering (e.g. UGS) shall focus on technical economy. It is verified that the UGS design proposal optimization model based on entropy weight-osculating value method is worth popularizing and applying, and it can be used as the beneficial reference for UGS design proposal optimization.