The influence of combining errors in the system for coherent combining of fiber lasers on the far field of output is studied numerically. Influences of the duty ratio, position errors and parallel errors on the distribution of far field are researched. The results show that the increase of duty ratio of output elements will raise the energy of the central lobe rather than change the central lobe′s average intensity; and position errors will decrease the energy of side lobes and the energy transfer efficiency of the system. It is found that the influence of position errors can be offset by increasing the output element′s duty ratio. Finally, the influence of parallel errors on far field is discussed and relative suggestion is provided.