Abstract: Development status of anhydrous sodium sulfate industry in China during the period of the 11th Five-Year Plan was briefly introduced.Hereby the improvement of vacuum device in anhydrous sodium sulfate production was put forward so as to effectively utilize the secondary steam and raise the utilization rate of heat energy.The manufacturing process and characteristics of anhydrous sodium sulfate were described in brief.In order to provide a reliable theoretical basis for the improvement，the heat energy of secondary steam and the mineral-dissolving required heat were carefully calculated by referring to mass of data.The design and model selection were made for the condenser of vacuum system and the implementation measures of improvement were also established.Through the improvement for the vacuum system，the target of energy saving and consumption reduction，production cost decline，and economic benefit increase was realized. 

Key words: anhydrous sodium sulfate, vacuum device, secondary steam, heat energy