The invention discloses a multi-path hydraulic system of a hydraulic excavator. The multi-path hydraulic system comprises a controller, an oil inlet pipe, an oil return pipe, a variable pump, a movable arm oil cylinder hydraulic system body, a bucket arm cylinder hydraulic system body, a bucket cylinder hydraulic system body, a rotary motor hydraulic system body and a walking motor hydraulic system body; an outlet of the variable pump is connected with the oil inlet pipe through a pipeline, and an inlet of the variable pump is connected with the oil return pipe through a pipeline; the movablearm oil cylinder hydraulic system body, the bucket arm cylinder hydraulic system body, the bucket cylinder hydraulic system body, the rotary motor hydraulic system body and the walking motor hydraulicsystem body are arranged between the oil inlet pipe and the oil return pipe. Each system body comprises an independent overflow valve and a proportional valve, a loading port is independently controlled, and therefore control is more flexible; meanwhile, the variable pump is adopted as an executing element, data of sensors is collected through the controller to adjust the flow, input into the system, of the variable pump in time, energy waste is avoided, and energy-saving control is realized.