Abstract: Electro-measuring method was used to measure the working stress in a typical used pressure evaporating tank under static and dynamic hydraulic loading tests.The stress and deformation conditions in all parts of the tank were thereby obtained.The safety allowance of the tank has been estimated,the location of stress concentration determined,and the improprieties in structural design discovered.Basered on these information, useful data and proposals were suggested for future design,manufacture and application of the tank.