The invention relates to a method for acquiring an atmospheric horizontal 
visibility field under a maritime dense 
fog condition, which comprises the following steps: collecting survey 
station soundingdata and the like of grid point 
meteorology and a related sea region, and performing 
quality control for the survey 
station sounding data to remove errors; determining a calculation region, a horizontal grid point number and a horizontal grid interval of a regional 
atmospheric model system RAMS model, interpolating the grid point 
meteorology data to all horizontal grid points of the RAMS model, preparing an initial condition and boundary condition field, and performing numerical integration for the RAMS model; and outputting and reserving forecast result data files, performing quantitative calculation by using an atmospheric horizontal 
visibility calculation formula, finally drawing the calculation result into a chromatic 
atmospheric visibility distribution graph, and outputting images interms of a JPG format. The method can effectively overcome the defects that the maritime 
atmospheric visibility observation 
station data is rare, the 
satellite remote sensing method cannot judge whether the cloud is grounded and the like in the prior art, provides quick and quantitative maritime atmospheric horizontal 
visibility field for various maritime activities, and has broad application prospect.