Amphibious excavator and walking hydraulic system thereof

The invention provides an amphibious excavator and a walking hydraulic system thereof. The walking hydraulic system comprises a main pump, a pilot pump, a left front walking driving device, a left rear walking driving device, a right front walking driving device, a right rear walking driving device and a working valve group, wherein the main pump is used for outputting working pressure oil; the pilot pump is used for outputting pilot pressure oil; the left front walking driving device is used for driving a left front wheel to walk; the left rear walking driving device is used for driving a left rear wheel to walk; the right front walking driving device is used for driving a right front wheel to walk; the right rear walking driving device is used for driving a right rear wheel to walk; theworking valve group is used for connecting the main pump with the left front walking driving device, the left rear walking driving device, the right front walking driving device and the right rear walking driving device. Duri