Based on the wide application of fingerprint lock in military, financial institutions, scientific research institutions, museums, office buildings, civil house and other fields. Therefore, an design of fingerprint lock is introduced. The system is composed by four main parts: microcontroller of Arduino Mega2560 as the control center of system; The system design uses 40 series optical fingerprint module as fingerprint sensor, which is used to input fingerprints, process and compare the recorded images, and store the fingerprint features into the fingerprint database; OLED liquid crystal display is used to display fingerprint information; the L298N motor drive module is used to drive the DC motor in the door lock, and the forward and reverse rotation control is performed to achieve the purpose of unlocking and locking. A large number of experiments show that the fingerprint lock is high intelligence, easy to use, huge storage of fingerprint, fingerprint input and unlock time is short, accurate identification of fingerprint and open the lock.