Abstract: Twice-conversion and once-evaporation are used during the production process of potassium sulfate and its by-product industrial salts by Glauber′s salt method，which is closed in a loop system.In the practical production，the whole system cannot reach the steady-state until the inflow and outflow of the water from the system get the balance.But it is hard to reach the balance due to the restriction of the product quality.In order to find out the cause and effect of the water imbalance and its corresponding solution，the effect of water imbalance on production quality and whole system was discussed on the basis of the theoretical analysis.That is，the water imbalance was expected to be solved through the following aspects， such as the adjustment of the conversion batching to improve the quality of potassium Glauber′s salt， the addition of vacuum crystallizer，the enhancement of evaporation to improve the quality of residue，the control of the addition of the process and non-process waters etc..

Key words: potassium sulfate；Glauber&prime, s salt method；water balance