Abstract: The all-fiber laser array with active phase control uses an all-fiber network to realize internal detection and control of piston phases, which is one of the important development directions of large-scale fiber laser coherent beam combining. It has the advantages of compact structure, no external feedback optical elements and easy expansion. The phase detection based on an all-fiber structure is employed in this paper. The principles of the active phase control method of an all-fiber laser array and the phase-locking process by fiber couplers are introduced. Then, the key techniques are summarized, and the proof-of-concept experiments are carried out based on optimum algorithms. The issue of π phase ambiguity is discussed and the numerical simulation result is given by double wavelength detection. At last, the research status is introduced, and the prospects are presented from the perspectives of expansion, power enhancement and applications.