Abstract: For micro-grids formed by multiple distributed sources of energy and the industrial park area grid, The selection of the black start power supply is a key factor in the rapid and reliable recovery of power supply after blackout. In this paper, the actual black start of regional power grid is taken as an example, two indicators were applied to the selection of a black start diesel generator set, and the MATLAB/SIMULINK simulation model is established, The adaptability of the selected diesel unit is verified, and the feasibility of using the emergency diesel generator as a black start power source in the thermal power plant is discussed.