Starting with the related theory of laser optics, the intensity distribution in the far-field is calculated by using the method of numerical simulation. Aiming at the square array, regular hexagon array and circular array with different sizes, the combing efficiency in different distances is calculated, analyzed and compared. The results show that the regular hexagonal arrangement has the highest combining efficiency, the square and the circular arrangement has the similar combining efficiency. By increasing the beam numbers, the combining efficiency can be improved. In the case of the large beam number, the effect is not obvious, but the increasing array can reduce the decreasing effciency speed due to the propagation distance.