The probabilistic fuzzy set (PFS) and probabilistic fuzzy logic system is designed for handling the uncertainties with stochastic and nonstochastic features. In this paper, an asymmetric probabilistic fuzzy set is proposed by randomly varying the width of asymmetric Gaussian membership function. And the related asymmetry PFLS is constructed to be applied to the rigid-flexible manipulator modeling. The performance discloses that the asymmetry-width probabilistic fuzzy set performs better than precious symmetric one. It is because the asymmetric probabilistic fuzzy set’s variability and malleability is higher than this of the symmetric probabilistic fuzzy set.