A method of preparing a high-strength carbon fiber composite bar with resin ribs on the surface, wherein the carbon fiber composite bar comprises carbon fibers and epoxy resin matrix, and has continuous spiral epoxy resin ribs on the surface of the said matrix, the method comprising the following steps: Step 1, drawing a plurality of carbon fiber bundles from a creel, adjusting the number of carbon fiber bundles as needed according to the diameter of the bar; through the number of fiber bundles, controlling a volume content of the carbon fibers in the bar blank to be in a range of 70%-78%, adjusting a drawing speed in a range of 300 mm/min - 600 mm/min, controlling a tension with a tension controller, adjusting the tension in a range of 5.88 N - 9.80 N; Step 2, pulling the carbon fiber bundles into an epoxy resin tank so that the carbon fiber bundles are impregnated with the epoxy resin; after moving out of the epoxy resin tank, putting into a preformed mold to obtain a bar blank with a predetermined diameter, wherein an inner diameter of the preformed mold is in a range of 2 mm - 10 mm; Step 3, when pulling the bar blank forward, winding a nylon belt on the bar blank, controlling the winding tension to ensure that the nylon belt is attached to the surface of the bar blank but not tightening the bar blank, the orientation of the carbon fiber bundles on the surface of the bar blank remains straight, the width of the nylon belt is 2 mm - 4 mm, and the thickness thereof is 0.5 mm - 1 mm; Step 4, pulling the bar blank with the nylon belt on the surface through 5 ovens successively, wherein the temperatures of the 5 ovens are set to be 150°C, 150°C, 160°C, 180°C, 180°C; after heated by the first oven, the epoxy resin inside the bar blank expands and has a good fluidity, starts to overflow from the inside of the bar blank and gradually fills up the gaps of the nylon belt; after treatment in the second oven, the epoxy resin gels; after treatment in the third oven, the epoxy resin is pre-cured; after the last two ovens, a post-curing process is completed; Step 5, after the curing is completed, unwinding the nylon belt from the surface of the bar, then spiral resin ribs are formed by the epoxy resin overflowing in the gaps of the nylon belt, and spiral grooves are formed at the unwinding part of the nylon belt. Step 6, winding the produced bars with resin ribs on a take-up machine after being pulled by a puller. Step 1, drawing a plurality of carbon fiber bundles from a creel, adjusting the number of carbon fiber bundles as needed according to the diameter of the bar; through the number of fiber bundles, controlling a volume content of the carbon fibers in the bar blank to be in a range of 70%-78%, adjusting a drawing speed in a range of 300 mm/min - 600 mm/min, controlling a tension with a tension controller, adjusting the tension in a range of 5.88 N - 9.80 N; Step 2, pulling the carbon fiber bundles into an epoxy resin tank so that the carbon fiber bundles are impregnated with the epoxy resin; after moving out of the epoxy resin tank, putting into a preformed mold to obtain a bar blank with a predetermined diameter, wherein an inner diameter of the preformed mold is in a range of 2 mm - 10 mm; Step 3, when pulling the bar blank forward, winding a nylon belt on the bar blank, controlling the winding tension to ensure that the nylon belt is attached to the surface of the bar blank but not tightening the bar blank, the orientation of the carbon fiber bundles on the surface of the bar blank remains straight, the width of the nylon belt is 2 mm - 4 mm, and the thickness thereof is 0.5 mm - 1 mm; Step 4, pulling the bar blank with the nylon belt on the surface through 5 ovens successively, wherein the temperatures of the 5 ovens are set to be 150°C, 150°C, 160°C, 180°C, 180°C; after heated by the first oven, the epoxy resin inside the bar blank expands and has a good fluidity, starts to overflow from the inside of the bar blank and gradually fills up the gaps of the nylon belt; after treatment in the second oven, the epoxy resin gels; after treatment in the third oven, the epoxy resin is pre-cured; after the last two ovens, a post-curing process is completed; Step 5, after the curing is completed, unwinding the nylon belt from the surface of the bar, then spiral resin ribs are formed by the epoxy resin overflowing in the gaps of the nylon belt, and spiral grooves are formed at the unwinding part of the nylon belt. Step 6, winding the produced bars with resin ribs on a take-up machine after being pulled by a puller.