The invention discloses a method for displaying a static warning optical signal at the rear part of an automobile, and belongs to the field of signal display devices. The method disclosed by the invention has the beneficial effects that a fault warning identification lamp with a long shot function is adopted, and red light beams can be backwards output from the tail part of the automobile, so a group of light spots or light bands are formed on the ground behind the automobile or under the view field of a driver of a behind automobile running in the same direction, and a marked fault warning mark optical diagram is irradiated or mapped, so that a dangerous process that a driver needs to place the fault warning mark due to fault parking is omitted through a way that the fault warning mark optical diagram is formed at the tail part of the fault automobile, and the personal safety of the person placing the fault warning mark is favorably ensured, besides an obvious fault warning signal can be rapidly provided for other vehicles running in the same direction behind the road where the automobile in fault parking is located, so that the behind automobile is reminded to keep a safe running distance, and a rear-end collision accident is prevented from happening; the method can be widely applied to the field of designing and manufacturing automobile signal lamp devices.