The invention belongs to the field of plant cultivation and relates to a high-altitude layering propagation method for sympodial bamboo. The method comprises the following steps of: breaking shoots of main culms, main branches and secondary branches, keeping main culms or secondary branches which are 1-3 meters in height on the middle lower part, cutting growing bamboo branches which are 1-2 centimeters away from the main culms, main branches or secondary branches, and keeping bamboo bases; and covering every culm ring of the main culms, main branches or secondary branches with a plastic bottom-free barrel bag, tightening the lower side of each barrel bag, filling a root inducing substrate which comprises a culm bud and a branch bud, tightening the upper side of each barrel bag to form a cylindrical container, and keeping the root inducing substrate in each barrel bag wet. Due to the adoption of the method provided by the invention, the problems of low survival rate of bare-rooted bamboo seedlings, high cost and severely insufficient bamboo seedling supply during the development of the bamboo industry are solved; and moreover, the method is easy to operate, materials are readily available, the cost is low, and large-scale popularization and application to production are facilitated.