A write-protection module for a storage device and the method thereof are disclosed. The write-protection module includes a power supply circuit, a fingerprint sensor, a database, and a microprocessor. The microprocessor for receiving the working power produced by the power supply circuit to maintain operation is respectively coupled to the power supply circuit, the fingerprint sensor, and the database. The fingerprint sensor receives the fingerprint input of a user, and the microprocessor receives the output signal of the fingerprint sensor and converts the output signal into an input cryptograph. Finally, the microprocessor compares the input cryptograph with a predetermined cryptograph stored in the database to produce a comparison information, and determines whether or not the user may access data.