Based on GFS background data and ARPS Data Assimilation System, visibility forecasts of 17 offshore sea fog cases in Qingdao from 2014 to 2016 are analyzed using the WRF model and three visibility algorithms in this paper. The results show that the FSL algorithm has advantages over the SW99 algorithm in forecasting the fog and its start time for coastal stations and shorebased stations, while the latter is better than the former for island stations. The hybrid CVIS algorithm improves the forecast accuracy of fog compared to single algorithm. The three algorithms basically overestimate the visibility, and the SW99 algorithm has the maximum root mean square error in the visibility forecast. In addition, by the SW99 algorithm for coastal stations and shore-based stations, the start time of fog forecast is basically later than the actual time, the end time of forecast earlier, and the duration of forecast shorter.