Method for improving denitrification performance of anaerobic ammonia oxidation system in sewage treatment

The invention relates to the technical field of sewage treatment, and provides a method for improving the denitrification performance of an anaerobic ammonia oxidation system in sewage treatment, which comprises the following steps: inoculating anaerobic ammonia oxidation granular sludge to the bottom of a reactor of the anaerobic ammonia oxidation system, adding hydrophilic polystyrene microspheres to the surface of the anaerobic ammonia oxidation granular sludge, and carrying out anaerobic ammonia oxidation treatment on the hydrophilic polystyrene microspheres; a microelement I preparation solution and a microelement II preparation solution are added into the inlet water; the trace element I preparation liquid comprises the following components: ferrous sulfate heptahydrate, ferrous titanate and disodium ethylene diamine tetraacetate; the trace element II preparation liquid comprises the following components: cobalt chloride hexahydrate, nickel chloride hexahydrate, sodium molybdate dehydrate, zinc chloride