Herein, Sb 2 S 3 thin films are successfully prepared by hydrothermal method using the mixing solution of SbCl 3 and sodium citrate as a novel Sb source. The influence of the growth temperature and time, growth solution volume on the properties of Sb 2 S 3 thin films, and the photovoltaic performance of the corresponding solar cells is systematically investigated. The results reveal that the thickness and Sb–O content in Sb 2 S 3 thin films decrease with the increase of the growth temperature and growth solution volume and decrease of the growth time. When the chemical composition and volume of the growth solution are 120 mM SbCl 3 , 276 mM sodium citrate, 180 mM Na 2 S 2 O 3 , 60 mM thioacetamide, and 28 mL, and the growth temperature and time are 150 °C and 2 h, the thickness and molar ratios of Sb–O:Sb–S/O in Sb 2 S 3 thin films are 295 nm and 0.14 and the corresponding solar cells achieve the power conversion efficiency (PCE) of 7.36%, which is the highest PCE in Sb 2 S 3 solar cells using hydrothermal method. Therefore, the effect of the growth temperature and time, specially the growth solution volume, on the thickness and Sb–O content in Sb 2 S 3 thin films is important for improving the PCE of Sb 2 S 3 solar cells.