The Qarhan Salt Lake plays a crucial role in China"s potassium fertilizer production, highlighting the essential relationship of water-salt (Here, the term “water-salt” refers to the coupled mass balance of water (liquid) and potash (solid + dissolved) in the Qarhan playa-lake system)for sustainable resource management and potassium fertilizer supply. This research investigates the complex evolutionary mechanisms governing the water-salt relationship in the mining region, influenced by climate change and human activities. This study utilised a comprehensive set of hydrometeorological data collected over a period of nearly three decades (1990–2024) to identify the evolving trends in the key factors influencing the water-salt relationship in the Qarhan Salt Lake mining area. Pearson correlation analysis was employed to reveal the evolution patterns and driving factors of the water-salt system in this region. The results indicate that over the past two decades (2000-2024), the climate in the mining area has transitioned from "warm and dry" to a "warm and humid". The volume of runoff of the recharged river has increased by more than 20%, accompanied by a temperature increasing of 1.5-2.0 °C. Conversely, a reduction of 18.5% has been noted in evaporation rates. Large-scale resource development activities have adversely affected water replenishment in the mining area, leading to a significant decline in the level of confined brine and a reduction in KCl grade. The implementation of artificial water replenishment and mineral dissolution has been shown to alleviate the severity of these negative impacts. The evolution of water-mineral interactions can be divided into three distinct stages. Initially, there is a transition from a naturally "hydrometeorological-dominated" state to a phase characterized by "combined natural and human influences." This is subsequently followed by a shift to a "human-dominated" trajectory. The key drivers of this transformation include climate warming, brine mining, and artificial water recharge for mineral dissolution. It is clear that brine extraction and artificial water recharge serve as the essential conditions for regulating the water-salt balance. These findings offer a scientific foundation for achieving effective water-salt balance and management in the Qarhan Salt Lake mining area.