1. A method for detecting a target object in a blind area of a vehicle, comprising: acquiring a frame of an image generated by shooting the blind area of the vehicle by a shooting device; extracting an image feature of an area where a predetermined detection gate is located in the image, wherein the area where the predetermined detection gate is located in the image is determined according to a shape and a size of the predetermined detection gate, a depth distance from the target object to the vehicle and a lateral distance from the target object to the vehicle; and the shape and the size of the predetermined detection gate are determined according to a type of the target object; and matching the image feature of the area where the predetermined detection gate is located with a matching template of the predetermined detection gate, to determine the target object, wherein a count of the number of the predetermined detection gates is 2n×m, wherein n is the number of the predetermined detection gates corresponding to the target objects which have same lateral distances and different depth distances on one side of the vehicle, and m is the number of the predetermined detection gates corresponding to the target objects which have same depth distances and different lateral distances on one side of the vehicle, wherein n and m are natural numbers larger than or equal to 1.