In order to study the influence of process parameters in laser water-jet machining on groove shape and metallographic structure of aluminum 6061,samples are machined on self-developed laser water-jet machining platform with different process parameters including laser power,laser repetition frequency,laser feeding speed and number of passes.Metallographic microscope is used to evaluate the cross-section shape and metallographic structure change of grooves machined by laser water-jet machining platform.Analysis of experiment results shows that laser repetition frequency has obvious influence on width of groove.Bigger laser power and lower laser repetition frequency can generate grooves with vertical side wall.And bigger laser power,lower laser repetition frequency,lower feeding speed and multiple processing have positive effect on generating grooves with bigger depth to width ratio.The metallographic structure has no change after laser water-jet machining.Based on those experiments results,a process parameter optimization method is proposed to realize machining of structure with high depth to width ratio and less heat affected zone using laser water-jet technology.