In order to address the denitrification problems of sewage plant effluent, type-A molecular sieve was synthesized by hydrothermal method with four different process schemes, using natural zeolite as a raw material that was collected from Gongyi, Henan Province. The synthesized product was examined for its adsorption performance on ammonia nitrogen, purity, crystal structure, morphology, porosity and other structural characteristics. The suitable process scheme for synthesizing high efficiency molecular sieve from natural zeolite was then explored. The alkali melting activation process was more effective than the direct alkali dissolution process in terms of the silicon source utilization from the raw material, while the product from silicon source purification synthesis scheme had a significantly improved ammonia nitrogen adsorption performance, with an equilibrium adsorption capacity of more than 20mg/g. It was associated with orderly crystal morphology, low impurity contents, and unobstructed pore channels, all of which were conducive to adsorption, diffusion and other mass transfer processes. By comprehensively considering the energy and materials consumption for synthesis and the adsorption properties of the synthesized product, the process scheme of alkali dissolution and silicon source purification was deemed as the suitable process plan to type A molecular sieve using natural zeolite.