The melting and sinking of sulfate saline soils is the main cause of secondary foundation damage. In order to investigate the melting and sinking patterns of sulfate saline soils with different salt and water contents under unidirectional warming conditions, indoor melting and sinking tests were conducted with sulfate saline soils in the central arid region of Ningxia as the research object. The results indicate that: (1) Melt and sink of sulfate saline soils can be divided into three stages depending on the ambient temperature: early warming (-24℃~5℃), the melting and sinking rate grows slowly; mid warming (5℃~20℃), the melting and sinking rate grows at a significant rate; late warming (20℃~24℃), the melting and sinking rate tends to stabilize at lower salt content and grows slowly at higher salt content; (2) When the moisture content is lower than the optimum moisture content, the 2% salt content soil reaches the maximum melting and sinking rate in the middle of warming, while when the moisture content is higher than the optimum moisture content, the 5% salt content soil reaches the maximum melting and sinking rate in the late warming period. (3) When the salt content is low (<2%), the maximum melting rate increases with the increase of salt content; when the salt content is high (>2%), the soil melting and sinking show two different trends depending on the water content: the maximum melting and sinking rate of soils with water content less than the optimal water content starts to decrease and tends to stabilize, while the maximum melting and sinking rate of soils with water content greater than the optimal water content continues to increase slowly; (4) The established model for predicting the maximum melt and sink rate has a good fit with the experimental values and can be used for the prediction and evaluation of the melt and sink rate of sulfate saline soils.