The invention belongs to the field of combined micro-machining and discloses an efficient micro-machining method and device for a non-conductive crisp and hard material. According to the machining method, ultrasonic vibration, electrolyzing, electric sparks, high-speed drill milling and other machining methods are organically combined to complete machining of non-conductive microstructures. In other words, a workpiece, a tool electrode and an auxiliary electrode are immersed into an electrolyte; the auxiliary electrode and the tool electrode are subjected to an electrolytic reaction; hydrogen evolution happens to the surface of the tool electrode connected with a negative electrode, and an insulation air film is formed; generation and homogenizing of the air film on the surface of the tool electrode are facilitated under the cavatition effect of ultrasonic vibration; and during machining, the tool electrode and the electrolyte on the surface of the workpiece generate spark discharge to puncture the air bubble film, and therefore a high-temperature erosion non-conductive workpiece material is generated. The machining device comprises a machine tool bed, an electrolysis-electrical discharge machining unit, an ultrasonic vibration worktable and a feeding worktable. Due to high-speed rotation of the spiral tool electrode and ultrasonic vibration of the workpiece, a clearance flow field can update the electrolyte efficiently. The efficient micro-machining method and device have the beneficial effects that efficiency and precision are high, and cost is low, and the efficient micro-machining method and device are very suitable for micro-machining of the non-conductive hard and crisp materials.