Propagation properties of four combined beams,i.e.,coherently combined single mode laser,incoherently combined single mode laser,coherently combined multi-mode laser and incoherently combined multi-mode laser,in turbulent atmosphere are analyzed by using extended Huygens-Fresnel principle. The propagation efficiency and effective range are numerically evaluated. The calculating results show that there is no significant difference in propagating efficiency and effective range of coherent or incoherent beam combining,and the single mode laser array has advantages in propagation efficiency over multi-mode beams. The advantage of coherent beam combining decreases with an increase in the intensity of turbulence,and there is no difference between coherent and incoherent combining in strong turbulence. The adaptive phase-locked single mode laser array that can correct tilted aberration is the best choice for developing a 100 kW tactical laser system.