The invention belongs to the technical field of water treatment, and specifically relates to a modified zeolite adsorbent capable of removing ammonia nitrogen and phosphate in water at the same time, and a preparation and regeneration method thereof. Cheap natural zeolite is modified by a sodium chloride solution, the contents of calcium and magnesium in zeolite are reduced, the ion exchange performance of zeolite on ammonia nitrogen is improved at the same time; then zirconium is loaded on the zeolite through a precipitation method, and zirconium has a specific adsorbing performance on phosphor, so the adsorption performance of zeolite on phosphate is improved. Cheap zeolite is adopted and modified through a simple modification method to prepare a bifunctional adsorbent capable of adsorbing ammonia nitrogen and phosphate at the same time. Moreover, through a provided regeneration liquid, the used modified zeolite adsorbent can be regenerated, the zeolite adsorbent can be effectively used repeatedly, and the adsorbent has a good application prospect.