The　work　aims　to　propose　a　new　method　of　preparing　fully　dense　metal　deposit　based　on　in-situ　micro-forging　assisted　cold　spray,　so　as　to　provide　a　low-cost　preparation　method　for　corrosion　protection　of　magnesium　alloy.　Big　sized　shot-peening　(SP)　particles　of　20vol.%~60　vol.%　were　mechanically　mixed　into　aluminum　powders　as　the　spraying　powder.　During　spraying,　the　deposited　aluminum　coating　layer　could　be　in-situ　forged　and　densified　by　the　big　sized　SP　particles.　Effect　of　in-situ　forging　strength　on　microstructure　and　corrosion　resistance　of　Al　coating　was　investigated.　SEM　was　adopted　to　analyze　the　microstructure　of　the　coating　and　electrochemical　tests　and　long-term　immersion　tests　were　carried　out　to　evaluate　the　corrosion　resistance　of　the　coating.　As　the　SP　strength　improved,　the　density　of　metallic　deposit　gradually　increased.　When　the　SP　particle　content　was　higher　than　40%,　fully　dense　adherent　Al　coatings　with　porosity　lower　than　0.3%　could　be　achieved　by　MF-CS　technique.　Electrochemical　tests　and　1000　h　immersion　test　in　NaCl　solution　showed　that　the　magnesium　alloy　covered　with　fully　dense　Al　coating　presented　the　same　corrosion　resistance　as　the　bulk　Al　and　the　corrosion　rate　decreased　by　over　two　orders　when　compared　with　that　of　unprotected　magnesium　alloy.　After　1000　h　salt　spray,　the　interface　between　coating　and　substrate　had　no　corrosion　products,　which　showed　that　the　coating　could　fully　isolate　the　corrosion　medium.　Meanwhile,　the　micron　level　passivation　film　occurred　on　the　fully　dense　coating　and　improved　the　corrosion　resistance　further.　Through　in-situ　micro-forging　assisted　cold　spray,　fully　dense　Al　corrosion　protection　coating　can　be　obtained　on　the　magnesium　alloy　at　lower　temperature　and　pressure.　The　technique　is　also　expected　to　be　used　in　other　fields　with　density　requirements　for　metallic　deposits,　such　as　preparation　of　high　thermal　conductivity　and　high　electrical　conductivity　coatings,　repair　of　metal　components　and　manufacturing　of　added　materials.　©　2019,　Chongqing　Wujiu　Periodicals　Press.　All　rights　reserved.