In the paper，The expression of the cost function of the eigenstructure extraction problem is discussed in detail. Through a proper transformation of the expression of the cost funtion，high-order neural network is introduced into the eigenstructure extraction problem. According to the method，the eigenstructure to be extracted is connected with the output of the network directly when the network is stable. The method is simple and direct，and can be used to track the eigenstructure adaptively. It opens a new area for the extraction of the eigenstructure.