The invention belongs to the technical field of traffic safety, and discloses a method for recognizing dangerous traffic behaviors of expressways. The method includes the steps that target vehicle indexes are acquired in real time at the current sampling moment according to a preset sampling interval, and whether a target vehicle is in the dangerous traffic behaviors currently or not is judged according to the acquired indexes; if not, 17 indexes of the target vehicle are acquired at a next sampling moment; corresponding judgment indexes are calculated according to the 15 indexes except for the type of the target vehicle and the traffic flow density; the judgment probability corresponding to the target vehicle is calculated through a dangerous traffic behavior recognition mode corresponding to a current road segment according to the vehicle type of the target vehicle, the traffic flow density and the corresponding judgment indexes; whether the target vehicle is in the dangerous trafficbehaviors currently or not is judged according to the judgment probability. The dangerous traffic behaviors can be accurately recognized in time, and the evaluation accuracy is high.