Under a warming climate, many areas of the world are experiencing drier conditions, leading to the rising lake evaporation rate and salinity. The salinization of a lake, or timescale needed to evolve from historically fresh to presently saline state, is important for understanding the paleo-hydrology and lacustrine geochemical cycling. Solute loss from transport (diffusion, advection, or density flow) and mineral precipitation in lake water are usually neglected in previous studies. Here, the salinization time of a saline lake in the Badain Jaran Desert, China is estimated based on the modified mass balance models of radium, barium, and chloride of lake water by considering the transport and precipitation loss of saline lake solutes. The calculated salinization time is 8,493.7 ± 1,559 years. The imbalance between imported solutes via groundwater discharge over the salinization time and their inventories in the present lake water suggests significant solute sinks through transport and precipitation. Specifically, sinks of barium, lithium, and strontium, have removed ∼ 10–100 times of the present-day inventories dissolved in lake water. These findings can guide the investigation of salinization processes in other saline lakes of similar hydrological and hydrogeological settings.