In this study, the solid-liquid equilibrium data of the quaternary system Mn2+, NH4+//SO42-,Cl--H2O and its two ternary subsystems (Mn2+,NH4+//Cl--H2O and Mn2+/SO42-,Cl--H2O) were measured by the isothermal dissolution method. For the two ternary systems, the solubility of the equilibrium liquid phase was determined. In the Mn2+,NH4+//Cl--H2O system, there are two invariant points and five crystallization regions. In the Mn2+//SO42-,Cl--H2O system, there are one invariant point and three crystallization regions. The solubility data of the quaternary system Mn2+, NH4+//SO42-,Cl--H2O were measured in the experiment. According to the theory of translation, the number of invariant points and crystallization zones of the quaternary system are predicted. The predicted results are the same as the experimental results, both of them have the same number of co-saturation points and crystallization zones. There are four invariant points and six crystallization regions in the quaternary system. It provides a theoretical basis for the water-salt system containing the quaternary system.