The invention relates to a biodegradable medical human body cavity channel inner bracket and a preparation method thereof. The biodegradable medical human body cavity channel inner bracket is prepared by performing crosswise weaving and surface coating treatment on a single or a plurality of degradable magnesium alloy long wires, and very high flexibility, so that the stimulation and damages of the bracket on the inner walls of the blood vessels and esophagi are lowered to the maximum extent; the bracket can be degraded and absorbed by a human body after operation and healing, so that the problem of endotheliosis restenosis caused by long-time existing of a non-degradable bracket in vivo is solved; due to the adoption of a surface degradable ceramic coating and a high-polymer film dual-protection layer, the corrosion resistance of the magnesium alloy wires can be effectively improved, and the degrading speed of the magnesium alloy wires is controlled; carried medicaments have long-term treating effects through slow release; the problem of difficulty in X-ray development of a light metal magnesium alloy is well solved through a carried developing agent; and the biodegradable medical human body cavity channel inner bracket can be used for expanding and supporting human body inner tube cavity channels such as narrow blood vessels, esophagi, bile ducts, intestinal tracts or urethrae and the like, and belongs to the technical field of manufacturing of medical instruments.