Using diamond abrasive and Ni-Cr-P pre-alloyed powder as grinding material and solder alloy, the Ni-Cr-P/ composite sintered body was prepared by brazing process. The effects of different brazing temperatures on the interfacial and grinding properties of the Ni-Cr-P/diamond sintered body were explored. The melting characteristics of Ni-Cr-P alloy were characterized by differential thermal analysis（DTA），the wetting effects and interface structure of Ni-Cr-P alloy on the diamond were observed by scanning electron microscope（SEM），and the bonding between diamond surface and the alloy was analyzed by X-ray photoelectron spectroscopy（XPS）. The results show that at the optimal brazing temperature of 940 ℃, some carbon elements on the diamond surface migrate into the liquid solder so as to form Cr—C bonds in the dense layer of Cr3C2，which effectively improves the wettability between Ni-Cr-P alloy and the diamond surface. Thus, the interface structure endows the compressive strength of single diamond particles and grinding ratio of the brazing grinding head with the maximum values（i.e., 36.83 N and 64.2）， which are significantly improved by 18.27% and 72.58% when compared to 850 ℃, respectively.