The surfaces of two kinds of diamond abrasives, the single crystal RVD and the polycrystalline PDGF1, were coated by brazing method, and the resin-bonded diamond grinding wheels were prepared with four kinds of abrasives before and after coating. The effects of brazing process on the surface morphologies and the mechanical properties of diamond abrasives were studied, and the grinding performances of cemented carbide machined by different grinding wheels were tested. The results show that a layer of filler alloy coating can be effectively coated on the surface of diamond abrasives by brazing-coating method, and the TiC interface bonding is formed between the coating and the diamond abrasive particles. Compared with the particles before brazing-coating, the impact toughness (TI) value of the RVD abrasive particles after brazing-coating decreases by 6%, while the TI value of the PDGF1 particles after brazing-coating increases by 42%. The resin-bonded diamond wheel made of brazing-coating PDGF1 abrasives has lower grinding force and higher grinding ratio, but the resin-bonded diamond wheel made by brazing-coating RVD abrasives has the opposite result. Under the same processing parameters, the surface topographies of cemented carbide grinded by four kinds of grinding wheels are similar, and the surface roughnesses are between 0.50 μm and 0.68 μm.