Traditional　online　communities　suffer　from　false,　repetitive　or　low-level　content,　with　blockchain　technology　able　to　solve　these　problems.　Specifically,　the　incentive　mechanism　is　the　blockchain’s　core　value,　including　positive　and　negative　incentive　mechanisms.　The　former　strengthens　people’s　behaviour　positively,　while　the　latter,　on　the　contrary,　adopts　mandatory　methods　such　as　punishment　to　eliminate　the　occurrence　of　certain　types　of　behaviour.　The　negative　incentive　mechanism　is　the　key　factor　to　solve　the　problems　presented　above　that　traditional　online　communities　face.　Specifically,　this　article　develops　a　solution　that　utilises　the　negative　incentive　mechanism,　based　on　the　classic　infectious　disease　model　(SIR　model),　introduces　smart　nodes,　puts　forward　the　SSIR　model　of　information　dissemination　in　the　blockchain　network　community,　and　establishes　a　set　of　differential　equations　reflecting　the　information　dissemination　rules.　Based　on　the　parameter　assumption　and　solving　the　equations　with　MATLAB,　this　article　compares　and　reveals　the　changes　of　different　user　types　on　the　SIR　and　SSIR　models.　Furthermore,　we　utilise　the　data　collected　from　the　Steemit　blockchain　community　and　Sina　Weibo　platform　and　apply　the　Social　Network　Analysis　method　to　compare　and　analyse　the　information　dissemination　between　the　blockchain　and　the　traditional　network　community.　The　research　results　highlight　that　the　negative　incentive　mechanism　in　the　blockchain　network　community　affords　a　more　rational　behaviour　of　user　information　dissemination,　a　simpler　interaction　between　users,　and　reducing　to　a　certain　extent　the　dissemination　of　‘distorted’　or　‘uncertain’　information.　©　The　Author(s)　2022.