Abstract: According to the serious wear of the bit and the insufficient flushing erosion in the underground directional borehole drilling operation process of Hongya ng No.2 Mine.The no pressure dipping method was applied to sinter two casing type PDC bits with each diameter of 96 mm.The paper introduced the sintering technical process of the casing type bit, mainly including the steel body manufacturing of the bit, the flexible die forming of the casing section, the design and processing of the C eramic die and the casing formulation design.A construction test of the directional drilling was conducted on the ZYWL-6000D mode over 1 000 m directional drilling rig with the drilling bit.A total drilling depth was about 3 000 m.During the construction process, the bit showed good mechanical performances and eliminated the bit excha nging in the construction process.