To improve the energy efficiency of high‑pressure water jets in ship rust removal operations，a high‑pressure gas‑liquid mixed jet nozzle was designed.Numerical simulation of the designed nozzle structure was conducted using LES and VOF methods.A comparative analysis was performed on the jet flow velocity，liquid phase distribution，liquid phase interface，and pressure on the impact target surface with and without aeration.Nozzle derusting experiments were carried out to verify the influence of the aeration process on jet performance.The results indicate that the aeration process significantly affects jet characteristics.By entraining air，momentum exchange occurs within the jet，enabling it to maintain a higher flow velocity in the throat.Under a water jet pressure of 195 MPa，the average flow velocity in the throat is approximately 400 m/s.Simultaneously，the aeration process promotes jet breakup into discrete droplets within the throat，forming a high‑energy gas‑liquid mixed jet that enhances the jet impact pressure.The maximum instantaneous impact pressure reaches 317.7 MPa，and the average impact pressure reaches 165.8 MPa，representing a 30.8% increase compared to the average impact pressure generated by a free jet.Compared to the inlet pressure，the average impact pressures of the aerated jet and the free jet decreased by 15.0% and 35.0%，respectively.This demonstrates that the aeration process helps reduce the attenuation of jet impact pressure.Under the premise of achieving the same impact effect，the aerated jet can reduce equipment operating pressure to some extent，which is beneficial for improving equipment reliability.Experimental results further validate the performance of the aerated jet nozzle.The findings provide guidance for the engineering application of aerated jets.