Drivers are used to steering when they meet obstacles in order to protecting the measure and lives. Freecod-data collector, dynamics GPS and the sensors of steering degree was utilized to study the rule of driver steering velocities, the relationships between maximum steering velocities and distance, and as well as maximum steering velocities and driving velocities were eastablished. The results show that drivers steering operation includes five periods and also indicates that driver maximum steering velocities is changing with distance in nagitive and driver maximum steering velocities is changing with distance in positive-linear. The regressive formulas were also given. This research help us to comprehend driver behavior under emergency.