The invention provides an ultra-short 
base line orientation 
estimation method for any formation. The method comprises the steps of initializing a 
delay adjustment matrix according to a received 
signal and a 
delay signal thereof, thus acquiring a 
delay adjustment 
matrix function, and initializing a distributed search network; detecting the 
arrival time of the signals, determining synchronous moments, sampling the synchronous moments, building a synchronous sampling moment set, thus acquiring a 
reference array element sampling sequence of the 
signal arrival moments; and computing the rotated distributed search network, computing a matched peak of each 
direction vector under the synchronous sampling moment set according to the 
reference array element sampling sequence of the signal arrival moments and the delay adjustment 
matrix function, and traversing orientation angles, wherein the direction of the maximum matched peak is the final estimated orientation vector. The ultra-short 
base line orientation 
estimation method for any formation provided by the invention can be expanded to various complex formations, and is stable in performance when the part of array elements is invalid, and high in 
estimation accuracy of the distance and orientation of the 
target signal source.