Abstract: An energy-saving control system of an excavator, including an engine, a main pump (1), a pilot handle, a pilot pressure pump (2), pilot control valves (4), a controller, a main control multi-way valve (3) and an execution mechanism. The main pump controls the execution mechanism via the main control multi-way valve (3). The oil paths connecting the main pump to the execution mechanism are provided with high pressure sensors (6) for transmitting signals to the controller. The main pump adjusts the flow rate thereof according to the pressure of a negative feedback oil path. The oil paths interconnecting the output end of the pilot handle with the main pump is provided with electromagnetic proportional reducing valves (7) and shuttle valves (8). A pilot oil path sequentially passes through the electromagnetic proportional reducing valves (7) and the shuttle valves (8) to control the flow rate of the main pump.