This study aims to reveal the stability characteristics and spatial distribution patterns of potassium (K), chloride (Cl^-) content, and potassium-chloride ratio (K/Cl) in flue-cured tobacco leaves of the main cultivated variety ‘K326’ in the Chuxiong tobacco-growing areas, so as to provide a scientific basis for the precise regulation of tobacco leaves quality. Based on the detection data of 6627 tobacco samples from the raw material bases of Chuxiong Cigarette Factory from 2018 to 2022, the stability of chemical quality was determined by the stability factor and critical value, the coefficient of variation (CV) was used to evaluate annual fluctuations, and township-level zoning analysis was carried out with ArcGIS technology. The results showed that the mean potassium content in upper, middle and lower leaves met the high-quality standard (1.60%-2.50%), but the overall level was low (5-year average: 2.09%-2.82%). The stability of lower leaves was poor (CV≥15%). The compliance rate in 2022 was close to 100%, which showed the optimization effect of cultivation techniques. The mean chloride content (0.44%-0.57%) met high-quality requirements, but annual fluctuations were significant (CV>50%). The proportion of lower leaves exceeding the target chlorine level reached 22.15%, and the chloride ion in the middle and lower leaves exceeded the standard in certain townships (e.g., Yipinglang Town in Lufeng City, Wande Town in Wuding County). The mean potassium-chloride (K/Cl) ratio (6.25-8.70) met the standard, but the compliance rate of sample points were only around 50%. The middle leaves had the worst stability, mainly due to higher and more variable chlorine content. The potassium-chlorine ratio consistently fell below the premium quality target in some regions such as Bajiao Town of Chuxiong City and Yipinglang Town of Lufeng City. In production practices, it is necessary to select tobacco varieties with low chloride content, weak chloride absorption capacity, high industrial acceptance, which can replace ‘K326’. The measures, such as appropriately increasing soil pH, applying organic fertilizer, using special fertilizer formulas, chloride ion inhibitors, and reasonable crop rotation, could also effectively reduce the chloride content in tobacco leaves, thereby increase the potassium chloride ratio of tobacco leaves. The potassium content of tobacco leaves in the Chuxiong area generally met the high-quality target requirements. However, the overall potassium content in tobacco leaves is still low and need further improvement. Precise attention should be given to regulating the potassium content in the upper and middle leaves at sampling points that fall below the target requirements for high-quality tobacco leaves. The strategies, such as using efficient potassium fertilizers, root-zone top-dressing of potassium fertilizer, application of bio-char or microbial fertilizers, and spraying dihydrogen phosphate or ethephon, could effectively increase the potassium content of tobacco leaves.