The invention discloses a rotary adjustable water waveguide laser processing device relating to a laser processing device. The rotary adjustable water waveguide laser processing device is provided with a laser, an inverted telescope, a lens cone, a pipe joint, a pressing sheet, flat glass, a water cavity, a first reflecting mirror, a focusing lens, a nozzle body, a positioning mortise and tenon, a compression screw, a nozzle fixing frame, a bracket, a water collector, a clamp, a numerical control platform, a camera, a water circulating device, a data acquiring, processing and controlling computer, an observation laser and a second reflecting mirror. When different processing zones are selected, light path adjusting links can be reduced, thus the efficiency is increased; the technical problems of narrow processing range and low efficiency in the background art part can be solved; the poor processing flexibility and other defects can be overcome; and in a cavity with a certain pressure for the equipment, stable water waveguide jet flow processing can be formed and laser can be guided to a laser region through water waveguide, thereby the application field can be widened and the efficiency can be increased to the greater degree.