A new approach for an all-fiber coherent beam combining by active phasing a fiber combiner is presented, and effect of fill factor of the fiber combiner on the all-fiber coherent combining is also numerical analyzed. Experimental results show that the power in the bucket (PIB) increases more than a factor of 2.35. The results validate the feasibility of coherent combining using a fiber combiner. The PIBs with different fill factors are calculated and the results show that the coherent combining is reduced with the increasing fill factor.