Fixed abrasive wire is considered as one of the most promising methods in slicing of large size semiconductor chip and function crystal because of its incomparable advantages. By contrast with the several existing methods of fixing super abrasive on wire, plating method has some advantages, such as short production cycle and low production costs. The plating technology of fixed diamond wire is a key technology for production and application of diamond wire. According to the demands of slicing hard and brittle crystal materials, basing on electrochemical deposition technology, a composite plating technology of fixed diamond wire is studied in this dissertation.Piano wire is chosen as the plated core of the fixed abrasive wire, diamond abrasives as the second phase, and their surface is pretreated before being plated. A kind of high speed sulphamate nickel-based electrolyte is chosen as basal electrolyte, the influences of plating process parameters on the micro-hardness of the nickel deposit have been studied by orthogonal experiments. It is concluded that the main influence factors on the micro-hardness of the nickel deposit are sulphamate concentration and electrolyte temperature, the deposition rate and quality in single-pulse mode are higher than that in DC power and double-pulse mode. Based on the results of experiments, the suitable plating parameters to obtain the hardest plating layer are selected.The influences of the methods of adding different size diamond particles into electrolyte, the relative directions and positions of the wire to the anode in the bath on plating process and quality of coating are investigated by experiments, the results show that uniform coatings can be obtained by putting wire into diamond particles, compared with the suspension mode by intermittent plate-pumping apparatus. Through symmetrical and ring position of anode, the surface area percentage of diamond particles in the composite coatings is as high as 50% because of the improvement of current distribution on the wire surface. The exposed height of diamond abrasive in the composite coatings can be controlled by changing the composite plating time and thickening time, diamond particle size the greater the time extended.The surface quality of nickel-diamond composite plating wire has been tested. The mechanical properties of fixed diamond wire trial-produced has been tested and evaluated, and its cutting performance has been studied by contrastive cutting experiments on the homemade simple cutting device. The results show that the fixed diamond wire has good dimensional homogeneity, and diamond particles are distributed evenly in the coatings.