Present inversion method for atmospheric visibility based on lidar technique is only able to inverse horizontal visibility accurately.Many disadvantages exist for slant visibility inversion in condition of inhomogeneous atmosphere such as rainy,cloudy and foggy.In order to measure slant visibility accurately,the principles of atmospheric visibility measurement with lidar was investigated,and experiments for visibility measurement with mobile lidar were conducted,especially a new iteration algorithm used for visibility inversion was posed.The algorithm is a combination of the well-known Collis slope method and Klett backward method,and it is able to retrieve the value of atmospheric visibility in different weather condition.The comparison experiment results show that this iteration algorithm agrees with Collis slope method and Klett backward method completely in condition of homogeneous atmosphere.For inhomogeneous atmosphere,this iteration algorithm can make up the shortages of Collis slope method and Klett backward method and retrieve the value of atmospheric visibility quickly,stably and accurately.