Disclosed are a prestressed drilling, anchoring and grouting anchor cable and a support method. The prestressed drilling, anchoring and grouting anchor cable comprises a hollow grouting anchor cable, a sleeve, a lock, a washer and a tray, the hollow grouting anchor cable is provided with a sleeve head, a drill bit is arranged at the front end of the sleeve, and the sleeve is provided with an anchoring hole and a thread. The hollow grouting anchor cable drives the sleeve to drill holes and advances inwards through the thread in reverse rotation, a metal nail at the front end of the sleeve head punctures an anchoring agent package inside the sleeve, anchoring agents are mixed and then discharged through the anchoring hole in the sleeve, the gap between the sleeve and a drill hole wall is filled with the anchoring agents, and the anchoring function is achieved. An exhaust pipe is arranged in the anchor cable, the anchor cable is provided with a plurality of lantern-shaped grouting sections, and grout vent holes are formed in the lantern-shaped grouting sections. The prestressed drilling, anchoring and grouting anchor cable integrates drilling, exhausting, grouting and anchoring, the tail of the grouting anchor cable is firstly tensioned and fastened, grouting is then performed, an anchored body becomes reinforced pre-tightening force concrete, loose coal rocks are drilled, anchored, grouted and supported once, the problem that the anchor cable does not easily enter drilled holes in the loose coal rocks due to sticking and hole collapse is solved, the support strength of surrounding rocks of a roadway is enhanced, and the carrying capacity of a rock mass is improved. The prestressed drilling, anchoring and grouting anchor cable is simple in structure, low in cost, easy in construction and fine in support effect.