The invention provides an emergency steering auxiliary function control device and method by combining a high-precision map with high precision positioning. Through the high-precision map and high precision positioning, the monitoring ability of the driver's driving environment can be improved, excessive dependence on sensors in the prior art is reduced, the auxiliary steering function can be timely controlled or inhibited in the unsafe driving environment, the device and the method has a good application prospect, at the same time, the application range of the auxiliary steering function is expanded and the safety performance of the device in the use process is improved.