The invention discloses method and device for preprocessing floating car data and relates to the field of intelligent traffic. The invention solves the problem that the prior art can not distinguish whether the data generated when a floating car generates GPS data in a parking state is passive parking data or active parking data . The method comprises the following steps of: filtering error data in the original floating car data; restoring the floating car data after filtering the error data in a unit of a car; and distinguishing the passive parking data and the active parking data from the floating data generated by each car according to the floating car data information. The embodiment of the invention is mainly applied to an intelligent traffic processing system.