An adjustable cavitator structure has a cavitator disposed at a head end of the underwater vehicle. The cavitator has a cavitator body, a center of which is connected to the head center of the underwater vehicle through a damper. The front end of the cavitator body is detachably connected with a head fairing device. The cavitator body is of a double-layer structure including a first layer and a second layer. A plurality of cavitator disc face retractable sheets are installed on the first layer and the second layer and are evenly distributed around the axis of the cavitator body, and are slidably connected with the corresponding first layer or second layer. A buffer driving mechanism for driving the cavitator disc face retractable sheets to slide in a radial direction of the cavitator body is installed at the head end of the underwater vehicle.