Capturing method and system used by an automobile data recorder

The invention discloses a capturing method used by an automobile data recorder. The capturing method comprises the following steps: detecting ambient light in real time by an ambient light sensor to obtain first light data; detecting the ambient light by the ambient light sensor when an object gets close, so as to obtaining second ray data; calculating a change value of the first ray data and thesecond ray data by a processor; determining whether the change value is greater than a preset value; and if the change value is greater than the preset value, performing capturing operation by cameraequipment in the automobile data recorder. The capturing method has the advantages that the non-contact gesture capture is realized by the light change detection; by setting judgement parameters of the automobile data recorder and the definition and duration of videos, the memory space occupancy rate is low, and effective evidence can be provided during traffic accidents; by setting the judgment parameters and picture clar