The separated final optics assembly (FOA) with high power has too many optical elements and complicated ghost distribution,which cause difficulty in ghost analysis of FOA. By using the Zemax software and Ghost software designed by ourselves, we analyze the ghost distribution of the FOA, establish the model to analyze the effects of the angle between the vacuum window and debris shield and the distance from the focusing lens to vacuum window or debris shield on the ghost distribution, use the model to analyze two ghost distribution schemes for the separated FOA, contrast the two designs, and get the final ghost distribution of the separated FOA.