A multi-protective cylinder convenient for bridge pile construction in cave-grow region is characterized in that thickness of the cylinder steel plate is calculated by formula of mechanics of materials; based on the required steel plate thickness, an A3 standard steel plate of 1.8m in width is rolled and welded to form a section of steel cylinder; and then 5-8 sections of steel cylinders are spliced to form a group of steel cylinder; multi groups of steel cylinders are spliced to form a bridge pile of designed depth; an outer cylinder 1 is spliced by multi groups of steel cylinders to a depth that can reach the underground cave or underground river; an outer cylinder 2 is spliced by multi groups of steel cylinders to a depth that can reach the geology structure of soil, rocks and sand gravels that can collapse easily; when the two cylinders is operated, the internal diameter of the inner cylinder is equal to the pile diameter of the designed bridge; and the diameter of the outer cylinder 1 needs to be larger than the bridge pile diameter by 25-35 cm. By the technology, the problem of severe over-amount concrete that generated by hole reaming when bridge pile construction is carried out in a cave special grow region can be thoroughly solved. Under the prerequisite of engineering quality and construction safety, the construction speed can be accelerated reasonably and the engineering cost can be effectively controlled.