AST3-1 is the second-generation optical photometric telescope at Dome A in Antarctica. In this study, photometric solutions of three eclipsing binaries comprising AST19571, AST21541, and AST38503 were determined for the first time using the light curves obtained with AST3-1. The light curves for the three binaries in the Galactic disk field were analyzed with the Wilson-Devinney method. We found that AST19571 and AST21541 are intermediate-contact binary systems with fill-out factors of f = 39.9(+/- 5.4) % and 36.4(+/- 4.7) %, respectively, and their mass ratios were determined as q = 0.275(+/- 0.0034) and 0.25(+/- 0.0024). AST38503 was shown to be a deep-contact binary system with a degree of contact of f = 66(+/- 33)% and a mass ratio of q = 0.314(+/- 0.03). Some light minimum times were derived for the three contact binary stars. The results showed that the period of AST19571 is increasing at a rate of dp/dt = +4.71 x 10(-7). This increase in the period could be explained by mass transfer between the components. The absolute parameters were estimated for the components of the three binaries.