At present,from the field application of various hydraulic oscillators,the problem of large pressure loss generally exists,then the ability of drilling fluid to assist rock breaking is reduced.Based on the principle of self-excited eddy current oscillation,an all-metal hydraulic oscillator was designed.In order to give full play to its performance and reduce the pressure loss,the internal structure of the oscillator needed to be optimized.Plackett-Burman design was used to screen the internal structural parameters,and the significant influencing parameters were determined as jet channel width,tool thickness and outlet diameter.The response surface method Box-Behnken Design was used to analyze the significant influencing parameters.The optimal combination of the internal structural parameters of the all-metal hydraulic oscillator can be obtained as jet channel width 14 mm,tool thickness 41.432 mm and outlet diameter 46 mm.Finally,the effectiveness of the optimization method was verified by numerical analysis.