A method for inputting a password and a device thereof are disclosed in the invention, relating to the information security field and solving the problem that a password input by a user is easy to be intercepted. The method includes steps that, a password inputting device acquires an instruction in accordance with ISO/IEC 7816 standard from an upper computer, and determines whether the instruction is a password checking instruction or not, and if it is not, the device sends the instruction to the smart card; or else if it is, the device receives the password input by the user, encloses it to the password checking instruction, sends the instruction enclosed with the password to the smart card, receives the result of executing the password checking instruction from the smart card, and sends the result to the upper computer. The solution of the invention is used for improving the security of inputting a password in avoidance that the password is intercepted when being transmitted.