In recent years, public security and traffic management departments at all levels have begun to build a large-scale intelligent monitoring and recording system for vehicles on road, based on which a large number of vehicle driving records information and pictures have been collected and stored. Aiming at the problem that the suspected vehicles of the same brand and type cannot be effectively identified which deliberately used other's number plate in the city-wide area, this paper proposes a city-wide deck suspected vehicle analysis algorithm based on regional space-time contradiction, and introduces the case demonstration of this analysis method.