In the visual analysis of geo-spatial trajectories, analyzing are often done in a large scale, but traditional methods of trajectory visualization often lead to the loss of some important information at such a large level. This paper proposed a new method of magnifying details in large-scale geo-spatial trajectory visualization. We constructed several fisheye lenses with exponential functions, and applied these fisheye lenses to the areas with a high density of trajectories. At the same time, based on the drawing rule that layouts should be balanced, we proposed a layout of these lenses using the rate of density to determine the radius of each lens. The results shows that details are magnified and more information are presented to analysts after the applying of fisheye lenses.