To solve the problems that the glass base slices of metrological gratings can not suffer the bad environments such as strong vibration and big impact, a new type material,Polycarbonate(PC),was chosen to replace the glass to manufacture metrological gratings. The optical characteristics,light transmittance,heat tolerance and the chemical resistance of the PC were analyzed and a cleanout method for the PC was given. On the basis of traditional manufacturing of gratings, a new manufacturing technology,namely,coating first and vacuum plating Cr afterwards,was developed. Finally,by taking the PC as a base slice,a PC optical resin metrological grating was produced in the vacuum degree of 1.2×10-3 Pa and evaporation distance of 150 mm, in which the film thickness was controlled by the quality of Cr. The PC metrological grating was observed in a 45× microscope.Results show that the edges of lines are vertical and no slips. The results indicate that the technology is feasible and technologic parameters are correct.It can provide an examination basis to develop precision measuring angle instruments.