Abstract: A low-damage processing device for complex microstructure by hybrid laser-ultrasonic processing in a steady flow area belongs to the field of precision special processing technology, and the device includes: a base, a workpiece clamping sliding table unit, a laser unit, a jet gun unit and a host computer. The workpiece clamping sliding table unit, the laser unit and the jet gun unit are provided on the base. The laser is applied vertically to the surface of workpiece. The jet gun unit emits a high pressure water jet at an angle of 45 degrees to the surface of the workpiece. The base is provided with a waste liquid collection device. The water jet and the laser act on the workpiece surface at the same time. The present disclosure strips the recast layer of the processed surface in real time, and improves the processed quality and performance of workpiece.