Emergency steering system based on hydraulic bridge road and engineering machinery

The utility model discloses an emergency steering system based on a hydraulic bridge circuit and engineering machinery. The emergency steering system comprises a hydraulic oil tank, a steering pump, a steering oil cylinder, a steering gear, a hydraulic control reversing valve, an emergency steering pump and the hydraulic bridge circuit. One port of the steering pump is communicated with the hydraulic oil tank, the other port of the steering pump is respectively communicated with the steering gear and the hydraulic control reversing valve, and the steering gear is communicated with the steering oil cylinder; the emergency steering pump is communicated in the hydraulic bridge road and is in transmission connection with the wheels; one port of the emergency steering pump is communicated with the hydraulic control reversing valve, and the other port of the emergency steering pump is communicated with the hydraulic oil tank; when the steering pump is in a normal working state, the emergency steering pump is in an