At present, large air flotation platforms are made of granite platform splicing, and the slots between the splices have a certain impact on the experimental effect. Aiming at the above problems, taking the time-variant characteristics of the micro-hole aerostatic bearing crossing through the slot as the research object, the physical model of the micro-hole throttling aerostatic bearing were established, and the dynamic process simulation of the bearing crossing the slot was carried out by using the dynamic mesh technology combined with CFD software and UDF. The effects of different air film thickness, inlet pressure and slot position on load capacity and pressure distribution were analyzed. The results show that the bearing capacity decreases rapidly when the slot reaches the distribution circle of the micro-hole, and the bearing capacity decreases to the minimum when the slot reaches the center of the bearing;with the increase of gas film thickness, the maximum loss ratio of load capacity increases and finally stabilizes to 0.6;when the slot is located outside the distribution circle of the micro-hole, the bearing surfaces between the edge of bearing and the slot is not work;by increasing the inlet pressure, the overall load capacity improves significantly, but the speed of load capacity loss becomes faster too.