A kind of new monolayer brazed diamond wire saw with both chemical bonding at the interface between diamond grits and brazing alloy and optimum grits distribution was made. And a machining performance comparative experiment was carried out between the sintered diamond saw from Italy and the brazed one mentioned above. The sawn material is marble with middle hardness. The testing results show that the wire saw with a brazed bonding diamond grid can achieve two to three times the working efficiency of conventional sintered diamond saw, and the corresponding service life can do 3~4 times. Furthermore, the grits of the brazed diamond wire fail mainly in micro fracture modes other than pull-out ones of the sintered diamond saw grits, indicating the strong retention of brazing alloy to the diamond grits. Almost no grits pulling out for brazed diamond wire saw is the key factor of its longer service life, and the optimum distribution and micro fracture of the brazed diamond wire grits raise the machining efficiency.