This paper proposes a fault diagnosis method for linear parameter varying time-delay system(LPVTD).Under the assumption that the parameters are convex and the system matrices can be of affine parameter dependence

by a linear fractional transformation(LFT)

the design of a fault filter can be equal to the design of a H∞robust controller.The existence condition and the method to get the gain of the controller are proposed.A simulation example demonstrates the effectiveness of the proposed method.