A method for detecting viscosity of liquid polysulfide rubber was explored. The influences of rotor speed, rotor type, polysufide rubber degassing mode, humidity and constant temperature time have been investigated on the viscosity measurement results using the type of viscosity meter. The optimum measuring conditions of liquid polysulfide rubber viscosity have been eventually determined. The viscosity test results have entirely met the requirements of measurement of liquid polysulfide rubber viscosity,and were stable and accurate as well. Furthermore, the expression requirements of viscosity measurement and testing results of liquid polysulfide rubber have been put forward. It was pointed out that this measurement method could be completely applied in viscosity measurement of liquid polysulfides.