Purpose:　The　number　of　online　communities　has　increased　rapidly　with　the　development　of　the　Internet.　Although　these　communities　provide　users　with　knowledge-sharing　channels,　the　enthusiasm　of　the　users　for　participation　remains　low.　Ecosystem　theory,　social　cognitive　theory,　and　some　other　theories　emphasize　the　importance　of　environmental　factors　and　hypothesize　that　the　behavior　of　users　is　affected　by　personal　factors　and　environmental　factors.　In　this　study,　the　authors　investigated　the　impact　of　platform　environmental　factors　on　knowledge-sharing　behavior　and　improved　the　platform　environment　construction　of　online　communities.　Design/methodology/approach:　First,　the　authors　analyzed　the　influencing　factors　of　online　community　knowledge-sharing　from　the　perspective　of　the　platform　environment,　constructed　a　research　model,　and　proposed　relevant　hypotheses.　Then,　the　authors　designed　a　questionnaire　and　conducted　a　survey,　and　finally　tested　the　hypotheses　by　using　the　method　of　structural　equation　model.　Findings:　The　results　showed　that　community　trust,　community　management,　community　incentive,　community　atmosphere,　and　community　information　protection　had　a　significant　positive　impact　on　community　knowledge-sharing　behavior.　Community　trust　played　a　significant　intermediary　role　in　the　relationship　between　community　management,　community　incentive,　community　information　protection,　and　knowledge-sharing　behavior;　community　information　protection　only　affected　knowledge-sharing　behavior　through　community　trust.　Additionally,　community　atmosphere　did　not　directly　affect　knowledge-sharing　behavior　through　the　intermediary　of　community　trust.　Practical　implications:　This　study　showed　that　theoretical　supplements　and　practical　guidance　are　significant　for　conducting　research　and　managing　knowledge-sharing　in　the　online　community.　They　help　community　managers　pay　more　attention　to　the　construction　of　an　online　community　platform　environment.　Originality/value:　In　this　study,　the　authors　analyzed　the　influencing　factors　of　online　community　knowledge-sharing　from　the　perspective　of　the　platform　environment　and　introduced　community　trust　as　an　intermediary　variable.　The　research　perspective　and　model　of　this　study　are　novel　to　some　extent.　©　2022,　Emerald　Publishing　Limited.