The invention discloses a sintered Nd-Fe-B magnet surface coating technology. The sintered Nd-Fe-B magnet surface coating technology comprises the following steps that firstly, oil removing, acid pickling and surface conditioning treatment are carried out on a sintered Nd-Fe-B magnetic black wafer in sequence; secondly, activation treatment is carried out on the Nd-Fe-B product treated through the first step; thirdly, nickel electroplating treatment is carried out on the Nd-Fe-B product treated through the second step; fourthly, chemical nickel tungsten phosphorus alloy plating treatment is carried out on the Nd-Fe-B product treated through the third step; and fifthly, baking treatment is carried out on the Nd-Fe-B product treated through the fourth step. According to the sintered Nd-Fe-B magnet surface coating technology, the nickel plating surface coating technology and the chemical nickel tungsten phosphorus alloy plating surface coating technology are combined to control the invasion of chloride ions to a Nd-Fe-B matrix, and the influence on the magnetic performance can be effectively reduced; and the bonding capability of a protective coating and the Nd-Fe-B matrix is improved, and good surface protection performance is achieved on Nd-Fe-B magnetic materials.