The invention relates to an intelligent monitoring and early warning device and method for the safety distance of an optical cable, and solves artificial uncertainty factors existing in manual inspection for the safety distance of the optical cable and a problem that detection cannot be performed on the safety distance of the whole optical cable in the prior art. The intelligent monitoring and early warning device comprises an optical cable, a suspension wire, a sliding mechanism and control equipment, wherein the control equipment comprises a detection unit, an obstacle analysis unit, a control unit, a communication unit and a solar power supply unit. According to the invention, whether an obstacle belongs to a tree or not can be distinguished, classified processing is performed on the safety distance, the processing is enabled to be more meticulous, early warning is enabled to be more accurate, and occurrence of a false early warning is avoided. The intelligent monitoring and early warning device can slide on the optical cable and detect whether there is an obstacle or not at both sides of all positions of the located optical cable and the obstacle distance, thereby being capable of understanding conditions of the obstacle safety distance of the whole optical cable more clearly and more visually, and solving a problem of inaccuracy because safety distance detection is only performed on one point traditionally and a problem of absence of a function of performing safety distance detection on both sides.