The first-principles calculations were performed to investigate the structural, elastic and electronic properties of typical face-centered cubic precipitate of Mg3Zn3Y2 under high pressure based on density functional theory (DFT). The optimized lattice constants at 0 GPa were similar to the other calculated and experimental results. The elastic constants of Mg3Zn3Y2 were calculated and analyzed. The bulk modulus （B）, shear modulus (G), Young''s modulus (E), Poisson''s ratio (ν), anisotropy index (A), melting points and hardness were further calculated based on the elastic constants. The calculation results showed that the mechanical properties of Mg3Zn3Y2 changed positively with the increase of pressure. In addition, the anisotropy index (A) of Mg3Zn3Y2 increased as the pressure increasing. The electronic density of states (DOS) of Mg3Zn3Y2 phase was analyzed, and it revealed that the structural stability of the phase was decreased as the increasing of pressure.