A hydraulic expandable anchor bolt comprises an anchor bolt body. A thread is arranged at one end of the anchor bolt body, a support plate is arranged at the other end of the anchor bolt body, and a nut is arranged outside the support plate. A telescopic support is arranged on the anchor bolt body, the upper end of the telescopic support is connected with an annular supporting plate, the lower end of the telescopic support is connected with an oil pipe, the oil pipe penetrates through the interior of a rod body and is connected with a hydraulic tank, and the hydraulic tank is connected with the tail end of the anchor bolt body. The anchor bolt body extends into a hole, the telescopic support is controlled by the hydraulic tank to support the annular supporting plate, and a soft pad of the annular supporting plate extends into a rock stratum groove. After support is completed, the anchor bolt can be recovered. Accordingly, the hydraulic expandable anchor bolt has the advantages of being free of environment limitations and easy to construct.