Multi-robotic　system　is　widely　used　in　exploring　in　large-scale　unknown　environment　and　performing　the　complex　tasks.　This　paper　presents　a　method　of　local　map　merging　for　Multi-robotic　system　using　RTM　as　communication　platform.　We　integrate　Scale-Invariant　Feature　Transform　(SIFT)　feature　matching　information　with　iterative　closest　point　(ICP)　algorithm　to　realize　the　local　map　merging.　We　use　the　USARSim　as　simulation　platform　to　realize　topological　map　and　map　merging　for　the　environment　in　which　mobile　robots　moving　using　the　proposed　method.　The　paper　details　the　architecture　of　the　proposed　method　and　gives　some　experiments　to　verify　the　effectiveness.