Scanning time-of-flight LiDAR (Light Detection and Ranging) is the predominant technique for autonomous driving. Mainstream mechanical scanning is reliable but limited in speed and usually has blind areas. This paper proposes a scanning method that uses an acousto-optic modulator to add high-frequency scanning on the slow axis of traditional automotive LiDAR linear scanning. It eliminated blind areas and enhanced the angular resolution to the size of the laser divergence angle. In experiments, this method increased the recognition probability of small targets at approximately 40 meters from 70% to over 90%, providing an effective solution for future high-level autonomous driving.