As　continuous-flow　microfluidic　biochips　technology　rapidly　advances,　its　automated　synthesis　methods　require　adapting　to　increasingly　complex　and　stringent　biochemical　applications.　In　particular,　with　the　introduction　of　time-sensitive　bioassays,　in　this　work,　we　present　a　timing-driven　high-level　synthesis　method　to　optimize　the　resource　efficiency　of　bioassays　considering　the　time　constraints.　Specifically,　we　investigate　the　existing　forms　of　time　constraints　and　propose　a　corresponding　flexible　modeling　approach　based　on　reaction-control　which　can　achieve　downward　compatibility　for　physical　design.　Additionally,　we　also　analyze　the　impact　of　storage　and　wash　on　time　constraints.　The　experimental　results　show　that　our　method　achieves　efficient　execution　and　low　devices　cost　while　satisfying　time　constraints.