With　the　development　of　wireless　sensor　networks　in　industry,　it　is　difficult　for　MAC　protocol　with　single　channel　to　meet　the　demands　of　combating　interference,　high　reliability　and　low　delay.　The　multichannel　MAC　protocol　is　a　promising　approach　to　meet　these　challenges.　IEEE　802.15.4　standard　is　the　foundation　of　ZigBee,　WirelessHART　and　ISA100.　This　article　proposes　a　multi-channel　MAC　protocol　based　on　802.15.4　standard　for　industrial　wireless　sensor　networks.　First　we　monitor　the　wireless　signal　in　industry　environment　-　The　Institute　of　Electronics　Chinese　Academy　of　Sciences,　and　establish　signal　interference　model　for　wireless　sensor　networks.　Then　a　maximum　discrete　channel　allocation　algorithm　is　designed.　Last,　in　order　to　realize　multichannel,　we　extend　802.15.4　MAC　protocol　by　adding　RTS(Request　To　Send)　and　CTS(Clear　To　Send)　in　CAP(Contention　Access　Period)　and　modifying　the　GTS(Guaranteed　Time　Slot)　list　structure　in　CFP(Contention　Free　Period).　Theoretical　analysis　shows　that　this　multi-channel　MAC　protocol　can　reduce　interference　and　increase　capacity　of　system　communication　effectively.　This　protocol　is　suitable　for　large　scale　network.　©　2012　IEEE.