Abstract: Based on uncertainty system with universal g rey mathematics,an uncertainty system model USM-1 to data processing of testing moisture regain of the ramie fiber was put forward. With this model,the data do n't need to be preprocessed and the generations of accumulate plus and subtract don't need to be made. The method can be used for model establishing on equal in terval,as well as on non-interval. It has high precision and easy to use.