Waterpower pulse cavitation jet well drilling device, method and drill bit

The invention discloses a hydraulic pulse drilling device with cavitation jet, which comprises a columnar body, wherein a fluid inlet section is provided at one end of the body, a fluid outlet section is provided at the other end of the body, and a fluid diversion portion for deviating the flow direction of the fluid, a pulse generator allowing the continuous fluid to generate pulse and a self-oscillation portion for allowing the fluid with pulse to generate resonance oscillation are sequentially provided between the fluid inlet section and fluid outlet section. The invention also discloses a self-resonating cavitation jet nozzle for drilling head, which improves the rock breaking effect of drilling head and rock cleaning effect at well bottom. The invention also discloses a hydraulic pulse drilling method with cavitation jet, which comprises during drilling work, converting continuous and stable fluid flow for impacting well bottom to pulse resonance flowing fluid; and injecting the pulse resonance flowing fluid into relatively static fluid to generate cavitation phenomena. The impact of well bottom with oscillating pressure reduces clip hold down effect, improves the rock cleaning and rock breaking capacity by jetting, and saves drilling cost.