Goldstein’s branch-cut algorithm is now the most classical one of the known phase unwrapping algorithms.It connects residues with branch-cut lines to neutralize their charges so that the integral path（can’t） stride over the branches in the process of phase unwrapping

thus avoiding pervasion of error.However

due to improper connections

this always brings about excessive branch-cut lines

and even many lines form a closed ’dead area’ that can not be unwrapped

especially when many residues exist.This paper presents a removal redundancy algorithm in phase unwrapping based on minimum spanning tree theory

and its implementation is described in detail.It can accurately remove the redundancies of the branch-cut tree and ensure the effectiveness of phase unwrapping.