Abstract: Based on analyzing the characteristics, wearing mechanism, welding material of the non-magnetic drill, the plasma arc surfacing technique was used to anti grinding treatment on non-magnetic drill surface, and non-magnetic plasma surfacing technique, drilling technique and anti abrasion layer technique were introduced. By the inspection, the relative permeability of hardfacing layer is 1.008 2, and its hardness is from HRC50 to HRC55. And the surfacing layer has no intergranular corrosion. A non-magnetic drill collar with ϕ178 mm and a non-magnetic pressure drilling pipe with ϕ127 mm were treated by plasma surfacing, and used in three wells in Sulige oilfield drilling, completion of vertical section, oblique section and horizontal section construction, the total working time is 568 hours.