A method for preparing a water-soluble curcumin mixture with high bioavailability includes the following steps: A) dissolving curcumin, vitamin C and ascorbyl palmitate in an ethanol aqueous solution, evaporating ethanol under reduced pressure, and vacuum drying to obtain a curcumin-vitamin C-ascorbyl palmitate co-crystal; B) high-speed emulsifying the curcumin-vitamin C-ascorbyl palmitate co-crystal and a wall material colloidal solution under vacuum, sequentially conducting a two-stage wet grinding, a homogenization and a potential adjustment to obtain an emulsified body; and C) subjecting the emulsified body to microencapsulation with a wall material twice and drying to obtain the water-soluble curcumin.