In this study, the mineralization of calcium carbonate in the mixed system with amino acid, polysaccharide and organic acid was comparatively studied, and CaCO₃ crystals were characterized by SEM, XRD and FT-IR. The results showed that the deposition of CaCO₃ was promoted by A-M, and the calcification rate was increased by 36% compared with the control group. The deposition of CaCO₃ was inhibited by organic acids, and the calcification rate of M-O, A-O and A-O-M decreased by 33%, 29%, and 17%, respectively. In the A-M, the main crystal composition of CaCO₃ was calcite, which also contained a small amount of vaterite. However, there was only calcite in M-O, A-O, A-O-M under the regulation of citric acid. The particle size of blocky calcite was 10 μm in A-M, and the vaterite was like a hollow circle with a particle size of 5 μm. Rod-shaped calcite with particle size of 5～15 μm and 3～5 μm was synthesized in A-O and M-O. A-O-M contained the most abundant organic matter, so that the nucleation rate was higher than the growth rate; the particle size of granular crystal was only 1～3 μm, and most crystals were incompletely developed. The research revealed the phenomenon of biomineralization in multi-component coexisting systems and emphasized the leading role of citric acid in regulating crystal nucleation and growth. The results obtained by the authors provide a reference for exploring the biomineralization mechanism in the subnival environment of Huanglong.