An accelerated specification introduced in this paper is developed during the process of solving the crack problem of a powertrain rear mounting structure. By sufficient analysis, the reason for such cracking is believed to be failure of fatigue under random loads in the proving ground. Meanwhile, due to special structuring of the rear mounting bracket, it is sensible to convert loads of various conditions to a one-simple-direction load case. Thus, acceleration of the test becomes possible.The accelerated test specification is resulted from the need of fast risk confirmation, as well as design verification, and is theoretically based on the damage equivalence principle . To realize it, RLD (Road Load Data) acquisition also plays an important role by providing the quantities of different test methods to be compared.With the problem solved, good correlation is also achieved between proving ground and the accelerated test. It greatly increases the design efficiency with both time and cost saved.