The invention provides an 
ammonium ion permselective 
nanofiltration membrane, a preparation method, application of the 
ammonium ion permselective 
nanofiltration membrane in 
sewage ammonium removal anda selective ammonium removal device, and belongs to the technical field of 
nanofiltration membranes. The ammonium 
ion permselective nanofiltration membrane comprises a 
desalination layer, a base 
membrane layer and a support layer which are sequentially arranged, and the base 
membrane layer contains an ammonium ion selective recognition 
receptor; and the ammonium ion selective recognition receptoris tripyrazole substituted 
benzene. Beneficial minerals such as 
potassium, 
calcium, 
sodium and 
magnesium in a 
water body can be intercepted, ammonium ions selectively permeate, and selective 
permeation, concentration and 
recovery of the ammonium ions are achieved; and low-pressure driving is adopted, so that the selective separation efficiency is improved, the cost is saved, and the 
energy consumption is reduced. The technical problem that ammonium ions cannot be selectively separated from 
potassium, 
calcium, 
sodium and 
magnesium ions through aperture screening of a traditional nanofiltrationmembrane is solved, the problems that a 
forward osmosis membrane method is low in ammonium removal efficiency, and osmotic balance limitation exists are solved, and the technical problems that a 
reverse osmosis method is high in cost and large in 
energy consumption, and beneficial ions such as 
potassium, 
calcium, 
sodium and 
magnesium ions cannot be reserved are solved.