The present invention provides a traffic information acquisition method and apparatus. The method includes the following steps that: the resolution angle of a lane to be detected with respect to a radar within a preset distance is acquired; the wavelength of current transmission signals of the radar is acquired; the synthetic aperture length of the radar is acquired according to the wavelength and the resolution angle; and the traffic information of the lane to be detected is acquired according to the synthetic aperture length. According to the traffic information acquisition method and apparatus of the invention, the traffic information of the lane is detected through vertically-distributed receiving/transmitting channels of the radar, and therefore, measurement distances can be increased, and the resolution of the lane and the accuracy of the traffic information can be improved.