The invention relates to the technical field of car 
electronics, in particular to a steering 
signal lamp 
automatic control method and 
system based on automatic driving. When the difference value K of the planned 
route curvature Kj and the curvature Kr of a road lane line in front of a 
car driving route exceeds the preset calibration value k0, meanwhile, the 
angular difference absolute value |theta| of a displacement point P1P of previous time and a displacement point PP2 of later time of a planned 
route meets the condition that the difference of |theta| and theta0 is larger than zero, and a point P2 is located on the right side of a P1P extension line, a right steering lamp is started; when the difference value K of the planned route curvature Kj and the curvature Kr of the road lane line in front of the 
car driving route exceeds the preset calibration value k0, meanwhile, the 
angular difference absolute value |theta| of the displacement point P1P of the previous time and the displacement PP2 of the later time of the planned route meets the condition that the difference of |theta| and theta0 is larger than zero, the point P2 is located on the left side of the P1P extension line, or the real-
time distance L of a barrier T in front of the same lane is smaller than the safe distance L0, a left steering lamp is started; and advance control over the steering 
signal lamps in an automatic 
driving mode is achieved by judging whether the steering lamps of a car are started or not in advance and turning off the steering lamps at appropriate time.