The invention relates to a hydraulic excavator and provides an excavator hydraulic system so as to solve the problem that construction is possibly affected when the hydraulic excavator cannot move in case of power outage. The excavator hydraulic system comprises a self high-pressure oil source, a self pilot oil source, a self oil tank, a pilot valve group, a main control valve and hydraulic executive components of the excavator. An oil source selection valve is additionally arranged between the main control valve and the self high-pressure oil source. A connector for introducing of an external high-pressure oil source is connected to the oil source selection valve. A shuttle valve is disposed between the pilot oil source and a pilot valve and a connector for introducing of an external pilot oil source is connected through the shuttle valve. Stop valves are connected between the main control valve and the self oil tank and a connector connected with an external oil tank is connected between the main control valve and the self oil tank. The external oil sources can be connected into the excavator when the excavator cannot move in case of power outage so that the excavator can move to leave a construction site, and accordingly the problem that construction is affected due to the fact that the broken-down excavator cannot move is avoided.