Abstract: Based on the common PDC preparation, synthetic polycrystalline diamond was treated by cobalt removal, reassembled and then synthesized again. Tests indicate that new PDC has better performance on abrasion resistance, impact resistance and heat resistance. The average volume abrasion ratio reached 5.20×10⁶, about 40% higher than that of normal products; the reducing of cobalt bond in diamond layer does not decrease the impact resistance; heat resistance is greatly improved. The cobalt removal could effectively reduce the cobalt content in the diamond layer, and improve the uniformity of bond distribution by inhibiting of local accumulation of the bond. Eventually, there appear more D-D bonds in diamond layer, thus improving the wear resistance of PDC product.