Abstract:The hot dry rock resource is mainly made up of volcanic with high temperature and poor drillability. In order to resolve the difficulties of low drilling speed and serious drilling tools wear, a set of φ127mm high-temperature turbodrill is designed and manufactured, which was tested in a hot dry rock well, the ROP were increased by 30.3% and 98.5% compared with φ165mm PDM + diamond bit and rotary table matching cone bit respectively. The experiment results show that this φ127mm turbodrill has reasonable structure design and is suitable for the high-temperature hot dry rock drilling.