This study proposes an optimal accelerated life test (ALT) design process for gears and bearings using a novel equivalent damage method (EDM). The process first calculates the damage incurred by each component under existing load duration distribution (LDD) conditions. It then generates an optimal ALT that applies equivalent damage while minimizing the total test time. We formulate this as a multi-objective optimization (MOO) problem with the objectives of minimizing both the total test time and the deviation from the damage profile of the LDD. The damage error for each component is treated as a constraint. The MOO problem is solved using the NSGA-III algorithm. To demonstrate its efficacy, the process is applied to a rotorcraft test gearbox. We compare the resulting ALT’s test time against the existing LDD and analyze the solution distribution on the final Pareto front. The results yield an optimal ALT that significantly reduces test time while preserving damage equivalency, thereby validating the effectiveness of the proposed design process.