The invention discloses a power matching optimal control method for a multi-power unit. The multi-power unit comprises at least two power units. The method comprises the steps that firstly, accordingto a current power state of a power battery pack, the current demand power and the peak power that each power unit can provide, the number of the power units which work at present is determined; and then, in the optimum working areas of the power units, according to the fuel consumption rate under different output power of the current power units which work, the output power of each power unit which works is determined with the objective of minimizing fuel consumption.