Security warning mirror for vehicle B column

The utility model discloses a security warning mirror for a vehicle B column, wherein front and back reflective mirrors with warning lights are mounted on the vehicle B column; the sight at the right front corner of a vehicle can be reflected by the front reflective mirror, so the condition at the right front blind area can be seen clearly by a driver conveniently; the sight at the back side of the vehicle can be reflected by the back reflective mirror, so the condition of following vehicles can be timely observed before a door is opened by a passenger at the back row who is about to get off the vehicle; and when the door is opened, the passenger is warned about the condition of following vehicles by the warning lights. The security warning mirror for the vehicle B column can be folded when being not used.