An optical network terminal with functions of detecting, recovering and blocking failures, and storing the information according to the present invention comprises: an uplink carrying out a function to communicate with a high level system; a communication port distributing or integrating the communication; a CPU managing distribution and integration of the communication; and a system power source for supplying power to the uplink, the communication port and the CPU, wherein the uplink comprises an optical module carrying out optical communication with the high level system; a MAC module controlling optical communication with the high level system; and a failure detection, recovery and blocking module for detecting optical output of the optical module, recovering failures and blocking optical output outside the MAC module. In accordance with the present invention, faster and specific failure solution can be provided using a low-cost microprocessor and its storage media.