In this study, we have developed a cavitation processing device with a mechanism that moves a nozzle capable of processing a wide coverage, such as the welding part of buildings or equipment that come in contact with the sea and require reinforcement work to be performed underwater. Technologies for generating cavitation include water jet peening and multifunction cavitation processing, which were incorporated into the mechanism for moving the nozzle. The water jet peening technique has a high-pressure inside the cavitation when forming the cavitation, on the other hand, multifunction cavitation processing technique has high-temperature and high-pressure inside the cavitation. Both of these techniques can be processed on object surface. In addition, in order to measure the performance of this processing equipment, the effects of processing damage suppression, surface roughness suppression, compressive residual stress, and hardness were investigated using pure Al and Al-Zn-Mg alloys. With the newly developed technology, the amount of damage during processing was small, the compressive residual stress and hardness increased, and the surface roughness was suppressed. Based on the above results, this processing technology can be used to reinforce a wide range of objects by increasing the strip-shaped surface modification area by moving the nozzle.