The invention relates to a multi-opening hydraulic reclamation structure based on a small-range hydraulic reclamation area, which comprises a hydraulic reclamation pipeline in which main hydraulic reclamation pipe openings are formed at intervals. An auxiliary hydraulic reclamation pipe opening is formed between adjacent main hydraulic reclamation pipe openings. Main gate plates are installed on the main hydraulic reclamation pipe openings of the hydraulic reclamation pipeline, and an auxiliary gate plate is installed on the auxiliary hydraulic reclamation pipe opening of the auxiliary hydraulic reclamation pipe opening. A multi-opening hydraulic reclamation method includes the steps that 1) the hydraulic reclamation area comprising a reclamation dam and a drain opening is arranged; 2), an initial hydraulic reclamation region is determined; 3), the beach face slope ratio is measured in real time in the hydraulic reclamation process; 4), the auxiliary hydraulic reclamation pipe opening is formed between the adjacent main hydraulic reclamation pipe openings; 5), the main hydraulic reclamation openings are used one by one according to practical conditions on the field, and the elevation is measured after beach faces of the bottoms of the adjacent two main hydraulic reclamation pipe openings are formed; 6), the flow of all the main hydraulic reclamation pipe openings and the auxiliary hydraulic reclamation pipe opening is inversely estimated according to the hydraulic reclamation fill amount required by the positions near the pipe openings; and 7), the hydraulic reclamation fill amount of the hydraulic reclamation pipe openings is set according to the flow. The hydraulic reclamation loss volume is effectively reduced, accumulation of hydraulic reclamation soil on the outer side of the drain opening of the hydraulic reclamation area is reduced, and the environment-friendly effect on the periphery of the hydraulic reclamation area is improved.