A method for protecting information based on a data card, comprising: selecting information which needs to be hidden in a terminal device (S106); and storing said information which needs to be hidden in a hidden partition of the data card that is connected to the terminal device via a USB interface (S108); before selecting the information which needs to be hidden in the terminal device, the method further comprises: acquiring input information of a user; determining that said input information meets a predetermined condition of said data card; and activating a hidden function of said data card by using said predetermined condition; characterized by : the data card being a data card adapted to access the Internet; wherein said predetermined condition comprises a short message with specific content of a specific user; wherein determining that said input information meets said predetermined condition of said data card comprises: determining whether an addressee's number of a short message in said input information is the number of said specific user, and if yes, determining whether the content of the short message in said input information is said specific content, and if yes, then determining that said input information meets said predetermined condition of said data card; or determining whether the content of the short message in said input information is said specific content, and if yes, determining whether the addressee's number of the short message in said input information is the number of said specific user, and if yes, then determining that said input information meets said predetermined condition of said data card. selecting information which needs to be hidden in a terminal device (S106); and storing said information which needs to be hidden in a hidden partition of the data card that is connected to the terminal device via a USB interface (S108); before selecting the information which needs to be hidden in the terminal device, the method further comprises: acquiring input information of a user; determining that said input information meets a predetermined condition of said data card; and activating a hidden function of said data card by using said predetermined condition; characterized by : the data card being a data card adapted to access the Internet; wherein said predetermined condition comprises a short message with specific content of a specific user; wherein determining that said input information meets said predetermined condition of said data card comprises: determining whether an addressee's number of a short message in said input information is the number of said specific user, and if yes, determining whether the content of the short message in said input information is said specific content, and if yes, then determining that said input information meets said predetermined condition of said data card; or determining whether the content of the short message in said input information is said specific content, and if yes, determining whether the addressee's number of the short message in said input information is the number of said specific user, and if yes, then determining that said input information meets said predetermined condition of said data card. <EOS>