In this paper, we describe orbital angular momentum entangled photon pair entanglement in atmospheric channel. The Von Karman spectrum of turbulence is used to create a model of two-photon pair entanglement. The effects of atmospheric turbulence on the entanglement of entangled photon pairs of different orbital angular momentum bases are analyzed. The obtained results are as follows because of the presence of atmospheric turbulence, the entanglement of entangled photon pairs decreases with the increase of the propagation distance z in the atmosphere channel. The entanglement of the entangled photon pairs decreases with the increase of transmission distance. The bigger the turbulence intensity, the faster the entanglement decline and the shorter the propagation distanceis. In the same intensity of atmospheric turbulence of the atmospheric channel, the bigger the orbital angular momentum index, the slower the entanglement decline and the further the propagation distanceis.