In nonlinear analog circuit fault diagnosis

considering different fault state of circuit

the output response of the circuit varies. A method for fault diagnosis of nonlinear analog circuits on the basis of multidimensional scaling（ MDS） is put forward

aiming at variable output response. This method can transform the difference of output response under different fault states into a low-dimensional fitting composition

so as to distinguish different fault types. Simulation result proves that under the condition of single fault of the circuit

the method has higher accuracy

can effectively classifying the different fault types

locate the faulty components

and observe the difference among variable faults intuitively in low-dimensional coordinate system.