In the previous study, we designed one personal rescue winch for high-rise building rescue. Its key requirement is to be small and light enough to suit users. In addition to using lightweight and reasonable materials as in the proposed winch design, in this study, we proceed to optimize the weight of one two-level gear train, which accounts for a large proportion of weight. The first stage is building a weight optimization problem model with seven independent variables, establishing one optimal algorithm, and investigating the variables by Matlab software. The other is replacing the web material of the gears and pinions with Aluminum 6061-T6 and optimizing their hole diameters and hole numbers through using Ansys software. The obtained result shows a significant weight reduction. Compared to the original design, the weight reduces by 10.21% and 52.40% after the first optimal and last stages, respectively.