The invention relates to an online monitoring system of a power distribution line fuse. The online monitoring system comprises a terminal device and a master station, wherein the master station comprises a server, and the terminal device communicates with the master station; and the server comprises a configuration management module, an alarm management module, a log management module, a system management module, a test management module, a system analysis module, a database management module and a network server module. The system provided by the invention helps the operation and maintenancepersonnel to find a fault point in time by monitoring and uploading information and data, such as the fault information of the fuse, the position of a fuse tube, fault current before the fuse, so as to quickly repair the fault and recover the power supply, and meanwhile, the fuse current collected by the system is used as the reference for the state maintenance of a fuse device.