For　the　appearance　of　recast　layer　and　micro-crack　in　laser　drilled　micro-holes,　electrochemical　machining　(ECM)　is　considered　to　reprocess　the　holes　to　eliminate　these　defects.　The　experimental　system　of　hybrid　processing　of　laser　beam　machining　with　ECM　is　developed.　Nickel　based　superalloy　GH4169　is　used　in　the　ECM　experiment　to　explore　the　influences　of　electrolytic　current,　concentration　of　sodium　nitrate　solution　and　parameters　of　pulse　electrochemical　machining　(PECM)　on　the　electrolytic　rate　and　the　removal　effect　of　recast　layer.　When　the　current　density　is　larger　than　13.8　A/cm2,　the　electrolytic　rate　is　proportional　to　the　current.　The　concentration　of　sodium　nitrate　solution　has　no　effect　on　the　electrolytic　rate　in　constant　current　ECM.　So　the　concentration　can　be　determined　by　the　current　and　the　voltage.　PECM　with　low　frequency　and　wide　pulse　or　with　high　frequency　and　narrow　pulse　is　beneficial　to　the　improvement　of　electrolytic　rate.　In　particular,　the　electrolytic　rate　can　get　the　maximum　value　at　the　frequency　of　1　kHz　and　the　duty　ratio　of　40%-60%.　PECM　is　accompanied　by　hydrogen　pressure　wave,　which　plays　a　good　role　in　stirring　the　electrolyte　in　the　machining　gap.　As　a　result,　it　can　improve　the　current　efficiency　and　increase　the　electrolytic　rate.　The　recast　layer　of　laser　drilled　micro-holes　can　be　removed　completely　by　choosing　appropriate　ECM　parameters.　©　2018,　Editorial　Office　of　Journal　of　Xi＇an　Jiaotong　University.　All　right　reserved.