The invention relates to the technical field of anchor rods, in particular to a self-expanding early-warning anchor rod. Comprising a rod body, an expansion mechanism and an early warning mechanism, the expansion mechanism comprises a shell, a water absorption cavity, an outer water absorption
sponge, an inner water absorption
sponge, a first push rod, a second push rod, a distance ring, a first expansion device and a second expansion device, and the water absorption cavity, the outer water absorption
sponge, the inner water absorption sponge, the first push rod, the second push rod, the distance ring, the first expansion device and the second expansion device are all arranged in the shell; the two ends of the second push rod are connected with the inner water absorption sponge and the second expansion device respectively, the distance ring is provided with a communicating hole and a baffle ring connected with the first push rod, the early warning mechanism comprises a
ringing device connected with the first push rod and a buzzing device connected with the second push rod, and the second expansion device is provided with a locking device. The expansion strength can be automatically adjusted according to the
water content of the soil layer, a reliable early warning function and an intelligent drainage mechanism are achieved, and the functions of
water content sensing, graded expansion, dual early warning and automatic drainage are achieved through the double-layer water absorption structure.