The invention discloses a novel excavator hydraulic system which comprises a motor, an inner-tooth-shaped elastic coupler, an oil filter, a radial plunger pump, a pressure gauge, a first electromagnetic overflow valve, a pressure regulating valve, a first two-position four-way electromagnetic valve, a direct-control balance valve, a first hydraulic one-way valve, a direct-control one-way sequence valve, a second electromagnetic overflow valve, a throttle valve, a second hydraulic one-way valve, a filter, a ball valve, an oil tank, a cylinder and a second two-position four-way electromagnetic valve. The second hydraulic one-way valve is connected with the filter and the cylinder. The first two-position four-way electromagnetic valve is connected with the pressure gauge, the first electromagnetic overflow valve and the pressure regulating valve. The novel excavator hydraulic system is high in transmission efficiency, and power performance and fuel application economy of an engine can be brought into full play.