The ultrahigh-pressure-jet-assisted drilling technique can increase the rate of penetration (ROP) greatly. A downhole boost compressor and an ultrahigh-pressure polycrystalline-diamond-compact (PDC) bit with dual-flow channels are the core techniques of ultrahigh-pressure-jet-assisted drilling. During recent years, the China University of Petroleum, Beijing (CUPB), has focused on theoretical and experimental research for example, the hydraulic structure and performance of downhole boost compressors, boosting theory, reversing control, rock-breaking mechanics under ultrahigh-pressure-jet conditions, and structural-design theory of ultrahigh-pressure PDC bits with dual-flow channels. On the basis of theoretical research, CUPB has designed and manufactured two generations of downhole-boost-compressor prototypes. At the same time, five oilfield-test experiments have been performed in the SINOPEC ZhongYuan oil field and CNPC TuHa oil field, China. As these experimental results showed, a downhole boost compressor and an ultrahigh-pressure PDC bit with dual-flow channels can increase ROP by over 50% under the five different sets of experimental conditions, and can meet the field-operation requirement. This research, outlined in the paper, played a leading role in the development of the ultrahigh-pressure-jet-assisted drilling technique. As one of the main techniques to increase ROP, ultrahigh-pressure-jet-assisted drilling is always a popular research project, and since the 1960s, research institutes worldwide have made significant progress (Veenhuizen et al. 1996, 1997a, 1997b; Butler et al. 1990). To date, the ultrahigh-pressure-jet-assisted drilling technique has gone through three main stages of development: the ground equipment to boost the pressure (1960s-70s), the ultra-high-pressure-drill system with dual-flow paths (1980s-90s) (Maurer 1980), and the downhole boost compressor (1990s-present) (Wang 2005, 2008). For downhole boost compressors, there are three different structures: turboboost, screw boost, and piston boost. Compared with the first two structures, piston-boost compressors have a much simpler structure, shorter total length, and better application for deviated wells and horizontal wells (Liu 1993; Meng 1997). CUPB has long been focused on research on a downhole boost compressor that is based on piston-boost structures. The main research results are as follows: boosting theory, downhole-boost-compressor hydraulic structural-design theory, downhole-boost-compressor material research, ultrahigh-pressure-jet hydraulic-character research, structural design of ultrahigh-pressure PDC bit with dual flow channel, and rock-breaking mechanisms of ultrahigh-pressure PDC bits with dual-flow channels. In 2005, CUPB successfully manufactured the first generation of prototypes of downhole boost compressors and ultrahigh-pressure PDC bits with dual-flow channels, and updated to the second generation in 2008. In this process, more than 10 repetitions of laboratory and field experiments were completed, and these results can play a positive role in the development of ultrahigh-pressure-jet-assisted drilling techniques.