Aiming　at　the　re-innovation　of　existing　products,　the　choice　of　innovative　methods　and　the　clarity　of　innovative　direction,　a　process　model　of　product　innovation　combining　reverse　engineering　(RE)　with　biologically　inspired　design　(BID)　was　proposed.　First,　existing　products　based　on　RE,　their　functional　models　were　established　through　structural　decomposition,　behavior　matching,　and　functional　construction.　Secondly,　product　user　needs　being　collected　through　demand　evolution　analysis,　importance　calculation,　and　function　evolution,　the　product　concept　function　was　re-innovated　to　form　a　new　function　to　be　solved　model.　Finally,　based　on　RE　modelling　method　of　the　biological　system　to　search　for　and　sort　out　biological　cases　using　the　established　biologically　inspired　design　auxiliary　system,　the　new　functions　of　system-assisted　solution　were　obtained　to　make　product　re-innovation　schemes.　Taking　the　protective　clothing　used　by　medical　staff　in　the　shelter　hospital　as　an　example,　it　is　verified　that　the　product　innovation　methods　of　RE　and　BID　have　a　good　feasibility.　©　2022　Editorial　Office　of　Chinese　Journal　of　Mechanical　Engineering.　All　rights　reserved.