Disclosed are a long-distance optical fiber detecting method, apparatus, device and system, and a storage medium. The method comprises: in response to a detection request of a target node on a to-be-detected optical fiber, determining a first and second sampling sequence that are formed by respectively propagating, on said optical fiber, a first and second optical signal respectively sent from each end of the optical fiber through an OTDR; determining a total length of the optical fiber; generating a detection result according to the first and second sampling sequence and the total length, and sending the detection result to the target node. By determining the first and second sampling sequence and combining the total length of the optical fiber, a detection result of the to-be-detected optical fiber is generated.