The invention provides a time sequence based RFID active anti-collision method. The method employs an RFID card self-transmitting mode. When an RFID reader and writer successfully receives a responding instruction ATQC of an RFID card, a WTRD instruction can be chosen and sent to enable all cards to enter a Ready state. Then, the transmission to other cards is aborted and the RFID card is chosen and operated which just received the corresponding instruction ATQC. In the method, it is also possible not to send any WTRD instruction, and continue to receive card data so as to complete the search of all cards in a radio frequency field. When the RFID reader and writer reads a plurality of RFID cards, the RFID reader and writer only saves the valid ATQC, and after the RFID reader and writer sends the REQC instruction, it does not have to send more instructions after it receives the valid corresponding ATQC instruction. Therefore, the time to send instructions can be saved; the received and sent data amount is saved; and the saving space is also saved.