We report first-principles studies the structural, electronic, and optical properties of the Fe2SiO4 fayalite in orthorhombic structure, including pressure dependence of structural parameters, band structures, density of states, and optical constants up to 30 GPa. The calculated results indicate that the linear compressibility along b axis is significantly higher than a and c axes, which is in agreement with earlier work. Meanwhile, the pressure dependence of the electronic band structure, density of states and partial density of states of Fe2SiO4 fayalite up to 30 GPa were presented. Moreover, the evolution of the dielectric function, absorption coefficient (alpha(omega)), reflectivity (R(omega)), and the real part of the refractive index (n(omega)) at high pressure are also presented.