The present invention discloses a method and device for operating telephone directories applied in a mobile terminal using a smart SIM card. The method comprising: after the mobile terminal is powered on, reading telephone directories in the mobile terminal and in the smart SIM card and constructing the first and second tables respectively; and when the mobile terminal detects that the first and second tables have been constructed, accomplishing a subscriber's operation on telephone directories in the first table and/or the second table, and after the first table is modified, using the modified first table to update the telephone directory in the mobile terminal, and after the second table is modified, using the modified second table to update the telephone directory in the smart SIM card. The device comprises a mobile terminal and a smart SIM card, wherein the mobile terminal comprises a processor, a storage, and a memory.