The invention relates to a method and system for data filtering. The method for data filtering comprises a first step of utilizing at least one RFID reader to collect data of a preset type in at least one RFID label and transmit the collected data to middleware; and a second step of utilizing the middleware to input the collected data in a preset finite state machine model, determine invalid data in the collected data according to output data of the preset finite state machine model and filter and/or merge the invalid data. According to the technical scheme, by utilizing the middleware, a finite state machine mode is adopted to effectively eliminate interference caused by labels outside the system, redundant label data in the system are integrated, valid label data are screened out to be rapidly effectively analyzed, and the risk caused by system misreading is also reduced.