Abstract: In allusion to situation that the item of power plant integrated with liquefied natural gas (LNG) terminal was used for a black start resource, the configuration principle of auxiliary power system and its concrete project were put forward. Firstly, the load variation during the black start process was mathematically simulated and calculated and the parameters of load variation were integrated, and on this basis the analysis was preceded. After theoretical analysis and derivation the principles, such as the diesel generator was used as the start power supply for the black start, the black start power resource and the emergency power supply were uniformly configured and in the system configuration the of middle-voltage devices were uniformly combined with low-voltage devices, were determined. Secondly, according to the results of theoretical analysis two different wiring schemes were constructed, and combining with the load model of the black start the mathematical calculation was implemented. Finally, it could be known from the techno-economic comparison that there were such features as less installed capacity, higher reliability, easy to operate, more economic to operate and maintain if the uniformly set black start diesel motor sets were adopted.