A　red-green-blue　(RGB)　random　laser　of　cascaded　polymer　slices　with　Ag　nanoparticles　doping　is　achieved　based　on　a　plasmonic　feedback　mechanism.　Three　polymer　solutions　dispersing　with　silver　nanoparticles　arc　sequentially　siphoned　into　a　300　mu　m　capillary　tube,　with　water　columns　isolating　between　adjacent　polymer　ink　columns.　Next,　the　plasmonic　random　laser　device　of　the　polymer　slices　doping　with　Ag　nanoparticles　is　constructed　after　the　solvents　and　water　evaporated.　The　Ag　nanoparticles　show　a　broad　plasmonic　resonance　spectrum　and　scatter　the　pump　light　in　the　polymer　slices　when　excited　by　the　pump　beam.　Therefore,　the　radiations　of　the　RGB　random　laser　are　enhanced　and　the　low-threshold　output　of　the　random　lasing　emits　from　the　micro　device.　The　thresholds　are　of　about　58　mu　J　cm(-2),　151　mu　J　cm(-2)　and　47　mu　J　cm(-2),　for　the　red-,　green-　and　blue-　components,　respectively,　and　the　chromaticity　is　presented　at　different　angles.　This　simple　and　straightforward　approach　has　the　potential　for　the　application　of　compact　integrated　random　laser　sources.