A fault detection method of an optical distribution network, wherein at least one optical identifier equipment (ID1-4, ID301-313, ID401-407, ID501-507) is disposed on a backbone fiber and is disposed on each branch fiber in the optical distribution network, and the optical identifier equipment uniquely identifies the backbone fiber through an address code and uniquely identifies each branch fiber through an address code, and the method comprises: sending an optical signal to the optical distribution network, wherein the optical signal is an optical signal for test; receiving the optical signal returned from each optical identifier equipment in the optical distribution network, performing signal processing on the returned optical signal, and obtaining an address code of each optical identifier equipment, wherein the performing signal processing on the returned optical signal and obtaining an address code of each optical identifier equipment comprises: converting, by an optical-to-electrical converter, the returned optical signal into a corresponding electric signal; converting, by an analog digital converter, the converted electric signal into a corresponding digital signal, and extracting a frequency component from the converted digital signal; and searching for correspondence between a frequency component and an address code according to the extracted frequency component, and obtaining an address code corresponding to the frequency component; and detecting whether a fiber corresponding to the address code has a fault according to the obtained address code of each optical identifier equipment; wherein the address code of the optical identifier equipment (ID1-4, ID301-313, ID401-407, ID501-507) comprises a segment address and an offset address, the segment address is used to identify each section of the optical distribution network, and the offset address is used to identify a backbone fiber, branch fibers, or an optical splitter in a same section. sending an optical signal to the optical distribution network, wherein the optical signal is an optical signal for test; receiving the optical signal returned from each optical identifier equipment in the optical distribution network, performing signal processing on the returned optical signal, and obtaining an address code of each optical identifier equipment, wherein the performing signal processing on the returned optical signal and obtaining an address code of each optical identifier equipment comprises: converting, by an optical-to-electrical converter, the returned optical signal into a corresponding electric signal; converting, by an analog digital converter, the converted electric signal into a corresponding digital signal, and extracting a frequency component from the converted digital signal; and searching for correspondence between a frequency component and an address code according to the extracted frequency component, and obtaining an address code corresponding to the frequency component; and converting, by an optical-to-electrical converter, the returned optical signal into a corresponding electric signal; converting, by an analog digital converter, the converted electric signal into a corresponding digital signal, and extracting a frequency component from the converted digital signal; and searching for correspondence between a frequency component and an address code according to the extracted frequency component, and obtaining an address code corresponding to the frequency component; and detecting whether a fiber corresponding to the address code has a fault according to the obtained address code of each optical identifier equipment; wherein the address code of the optical identifier equipment (ID1-4, ID301-313, ID401-407, ID501-507) comprises a segment address and an offset address, the segment address is used to identify each section of the optical distribution network, and the offset address is used to identify a backbone fiber, branch fibers, or an optical splitter in a same section.