The　removal　of　major　contaminants　in　different　industries,　such　as　heavy　metals,　pharmaceutical　and　personal　care　products　(PPCPs),　ammonia　nitrogen,　phosphate　and　fluoride　has　become　one　research　focus　in　the　field　of　water　decontamination.　Adsorption　is　widely　used　in　the　removal　of　water　pollutants　due　to　its　advantages　of　simple　operation　and　cost-effectiveness.　Compared　with　traditional　adsorbents,　biochar　exceeds　in　its　superiorities　of　abundant　raw　materials,　large　surface　area　and　low　cost,　but　the　abundance　of　its　surface　functional　groups　is　limited.　The　active　absorption　sites　of　biochar　can　be　improved　via　appropriate　modification,　thereby　enhancing　its　adsorption　performance.　In　this　paper,　biochar　modifications　and　the　physicochemical　properties　of　biochar-based　composites　were　reviewed　according　to　the　types　of　modifying　agent,　the　synthesis　methods　and　sequences.　Combined　with　the　latest　research　reports,　the　adsorption　of　biochar-based　composites　for　heavy　metals,　PPCPs　and　other　aqueous　pollutants　was　summarized　in　terms　of　synthesis　method,　adsorption　performance　and　mechanism.　Finally,　some　suggestions　with　respect　to　improvement　in　biochar-based　adsorbent　optimization　and　applications,　especially　to　regeneration　and　resource　utilization　were　proposed.　©　2019,　Chemical　Industry　Press.　All　right　reserved.