C.　pyrenoidosa　,　a　species　of　microalgae,　has　been　recognized　as　a　viable　protein　source　for　human　consumption.　The　primary　challenges　in　this　context　are　the　development　of　an　efficient　extraction　process　and　the　valorization　of　the　resultant　waste　streams.　This　study,　situated　within　the　paradigm　of　circular　economy,　presents　an　innovative　extraction　approach　that　achieved　a　protein　extraction　efficiency　of　62　%.　The　extracted　protein　exhibited　remarkable　oil　-　water　emulsifying　performances,　such　as　uniform　morphology　with　high　creaming　stability,　suggesting　a　sustainable　alternative　to　conventional　emulsifiers.　Additionally,　hydrothermal　liquefaction　technique　was　employed　for　converting　the　residual　biomass　and　waste　solution　from　the　extraction　process　into　biocrude.　A　biocrude　yield　exceeding　40　wt%,　characterized　by　a　carbon　content　of　73　%　and　a　higher　heating　value　of　36　MJ/kg,　were　obtained.　These　findings　demonstrate　the　promising　potential　of　microalgae　biorefinery,　which　is　significant　for　paving　toward　circular　economy　and　zero　-waste　society.