The　odor　emission　from　wastewater　treatment　plants　(WWTPs)　has　sparked　widespread　concern,　with　H2S　emerging　as　one　of　the　most　worrisome　odors.　End-of-pipe　treatment　has　been　the　predominant　method　for　addressing　H2S　in　recent　decades.　It　is　plagued　by　complexities　in　operation　and　high　costs.　Technologies　for　insitu　H2S　control　have　garnered　increasing　attention　due　to　their　high　economic　efficiency　and　low　energy　consumption.　However,　technologies　for　in-situ　H2S　control　in　WWTPs　still　need　to　be　further　systematically　summarized　and　categorized　while　technologies　for　in-situ　H2S　control　for　overall　WWTPs　are　still　lacking.　This　paper　provides　a　retrospective　analysis　of　the　principles,　drawbacks,　and　limitations　of　traditional　technologies　for　insitu　H2S　control　while　highlighting　several　promising　and　advanced　technologies.　Characteristic　analyses　of　these　technologies　are　conducted.　The　shortcomings　they　must　overcome　and　the　primary　challenges　they　face　in　the　implementation　of　WWTPs　are　identified.　Finally,　the　paper　forecasts　the　future　research　directions　and　proposes　strategies　to　tackle　the　associated　challenges　of　technologies　for　in-situ　H2S　control.　We　emphasize　the　necessity　of　prioritizing　the　overall　management　of　WWTPs,　with　a　primary　focus　on　process　reduction-oriented　operational　optimization　measures,　advocating　for　the　practical　adoption　of　technologies　for　in-situ　H2S　control,　synergistic　integration　of　multiple　treatment　modalities,　and　utilizing　mathematical　methods　such　as　machine　learning　to　optimize　design　parameters　and　solutions.