Compared with traditional processing methods,femtosecond laser has a ′cold′ processing effect,resulting in high processing quality.However,there is a limitation in processing depth when creating micropores with a diameter of less than 200μm.To address the difficulties in machining deep micropores,a comprehensive study is conducted using the single factor variable control method.The effects of femtosecond laser power,fill spacing,repetition frequency,single layer feed amount,and scanning speed on the quality of stainless steel micropores with a target diameter of 100μmand depth of 1mm are systematically investigated.A comparative analysis is performed on the entrance diameter,exit diameter,and taper of micro holes processed via two techniques:laser annular processing and annular spiral combined processing,leading to the optimal processing technique.The results show that the highest micro hole qualityis achieved under the combined processing methodwith parameters set as follows:a repetition frequency of 75 kHz,a scanning speed of 30mm/s,a single layer feed amount of 10μm,a fill spacing of 8μm,and a laser power of 24 W.The entrance diameter of the micropore is 158.38μm,the exit diameter is 69.75μm,and the taper is 0.04°.