The invention relates to a preparation method of a single crystal high Al component AlxGa1-xN ternary alloy nanorod. The method includes: firstly preparing a silicon substrate with deposited thin layer aluminum powder having a deposition thickness of 0.5-1.0mm, then spreading metal Al powder flatly at one end of a reaction boat, placing the silicon substrate above the powder, dripping Ga liquid tothe other end of the reaction boat, putting a reaction device into a quartz test tube with one opening end, performing sealing and vacuum pumping; when the vacuum degree is less than or equal to 5Pa,introducing argon to fill the whole atmosphere with argon, then adjusting the argon flow rate, conducting heating to 900-1000DEG C, adjusting the argon flow rate to 40-60sccm, at the same time, introducing ammonia with the same flow rate to argon, keeping the state for 1-3h, and conducting furnace cooling, thus obtaining the high Al component single crystal AlxGa1-xN ternary alloy nanorod, wherein the adjustable range x of the Al component is less than or equal to 0.92 and greater than or equal to 0.88. The method has the advantages of simple process, good reproducibility, no phase separation, low production cost, no adding of any catalyst and template, and is easy for industrial popularization and application.