Microfluidic technique was employed to precisely modulate both the microenvironment and composition, enabling the dynamic assembly of curcumin, soy protein isolates, and rhamnolipid into ternary nanocrystals through hydrogen bonding and hydrophobic interactions. As the concentration of rhamnolipid increased, the loading capacity of curcumin in ternary complex nanocrystals rose from 4.23 % to 10.82 %, while its water dispersibility and bioaccessibility enhanced by 141.94- to 664.67-fold and 5.11- to 6.49-fold, respectively. Moreover, the stability of curcumin in ternary complex nanocrystals was significantly enhanced during both storage and exposure to UV light. The longest half-life of curcumin in the nanocrystals increased from 65.39 days to 385.08 days during storage at 25 °C, and from 87.74 min to 198.04 min under UV light. These findings provide important insights for the development of bio-assemblies, and the resulting complex nanocrystals can be used as pigment or bioactivity in foods, cosmetics and pharmaceuticals.