Pre-stressed anchor cable with fracture pre-warning function

The invention discloses a pre-stressed anchor cable with a fracture pre-warning function. The pre-stressed anchor cable with the fracture pre-warning function is composed of an anchoring steel strand, a pre-warning steel strand and a pre-warning device, wherein the pre-warning device is composed of a pre-stretching spring and a sliding rod, wherein the pre-stretching spring is installed in an anchor cable hole and fixedly clamped with the pre-warning steel strand, and the sliding rod penetrates through an anchorage device; the tensile strength of the pre-warning steel strand is lower than that of the anchoring steel strand according to a certain proportion, or the applied pre-stretching stress is higher than that of the anchoring steel strand according to a certain proportion. Various steel strands generate synchronous tensile deformation in the working process of the anchor cable. The pre-warning steel strand reaches tensile strength to be broken prior to the anchoring steel strand, the spring of the pre-war