The invention relates to the technical field of boiler combustion utilization, in particular to a deep peak-shaving and combustion-stabilizing system of a direct-blown coal-fired unit. The deep peak-shaving and combustion-stabilizing system of the direct-blown coal-fired unit comprises a boiler and is characterized in that deep peak-shaving combined combustion-stabilizing combustors are arranged in a secondary air chamber of the bottom layer of the boiler, powder inlets of the deep peak-shaving combined combustion-stabilizing combustors are connected with outlets of separators through primaryair pipes, and the separators are mounted on a coal pulverizer. According to the deep peak-shaving and combustion-stabilizing system of the direct-blown coal-fired unit, the structure is simple, pulverized coal is ignited through an igniting oil gun, after combustion of the pulverized coal is stable, the oil gun is quitted, the system can continuously and stably operate without accumulating powderand coking, later maintenance is less, and energy saving, environmental protection and stable operation of the boiler under low load are facilitated.