The invention discloses a backing plate for PCB boring and a manufacturing method thereof. The manufacturing method comprises orderly adding 50-70wt% of novolac epoxy acrylate resin, 20-50wt% of a filler and 0-10wt% of a diluent into an agitator tank, heating the materials to a temperature of 40-60 DEG C, carrying out stirring mixing for 30-60min, adding 0.5-5wt% of a photoinitiator into the mixture, carrying out stirring for 10-15min, carrying out cooling and material discharge to obtain composite resin, coating upper and lower surfaces of a wooden fiber plate as a substrate with the composite resin and carrying out cure under preset conditions to obtain the backing plate. The backing plate for PCB boring has obviously improved surface hardness, effectively reduces burr produced in boring and improves PCB boring processing efficiency.