This　paper　presents　a　collaborative　obstacle　avoidance　algorithm　of　multiple　bionic　snake　robots　in　fluid　based　on　IB-LBM.　The　method　can　make　the　multiple　bionic　snake　robots　avoid　different　obstacles　in　the　fluid　under　the　control　of　the　improved　Serpenoid　curve　function.　The　proposed　method　has　high　parallelism,　can　simulate　the　complex　non-linear　phenomenon　of　the　multiple　snake　robots,　deal　with　the　complex　boundary　conditions　of　the　robot,　and　reduce　the　conversion　of　the　computational　grid.　Firstly,　a　non-linear　fluid　model　is　established　by　LBM,　which　solves　the　non-linear　problem　that　the　classical　Navier-Stokes　equations　cannot　explain　the　random　motion.　Secondly,　the　force　source　boundary　model　of　multiple　bionic　snake　robots　is　established　by　IBM,　which　saves　the　calculation　time,　improves　the　calculation　efficiency　and　system　stability.　After　that,　each　bionic　snake　robot　is　given　a　special　force　to　make　the　robots　collaborate　with　each　other　and　non-colliding　with　each　other　in　the　process　of　the　obstacle　avoidance.　Finally,　through　simulation　experiments,　the　trajectory　of　multiple　bionic　snake　robots　avoiding　different　number　of　the　obstacles　in　the　fluid　is　analyzed　and　the　collaborative　obstacle　avoidance　process　of　multiple　bionic　snake　robots　in　fluid　is　observed.　The　validity　of　the　collaborative　obstacle　avoidance　algorithm　of　multiple　bionic　snake　robots　in　fluid　based　on　the　IB-LBM　is　verified.　(C)　2021　ISA.　Published　by　Elsevier　Ltd.　All　rights　reserved.