On the basis of the mathematical processing theory of uncertain information,this paper sets up the uncertain quantized expressions of the experts in the same field,defines the operation and operation law between expressions,and gives uncertain decision model of composition.

According to Knight s classification of risk and uncertainty, two branches of decision theory, decision under risk and decision under uncertainty, were derived.

That established the model of unascertained decision.

Analyzing the principles and main factors in the location of a distribution center, the paper quantifies every factor in the process of location decision adopting a method of unascertained quantification, and then it makes the last estimation according to the data with unascertained decision in order to get a more reasonable scheme.

Now in the field of fault diagnosis, the uncertain problems becomes the chief problem to solve, and the Bayesian networks has become the hotspot because its most efficient theory model for solving uncertain problems and expressing uncertain information.