A 3rd-order precision upwind scheme and a 2nd-order precision central difference scheme were adopted to directly solve two-dimensional unsteady N-S equations,and to study the flow field characteristics of the region after pres- sure drop recovery of aerostatic bearing with slot-restricted. The flow field state of gas film center at the same position was calculated by using the Reynolds equation and was compared with the calculation results of the direct numerical simulation method. The results show that calculation results of Reynolds equation and N-S equation are basically the same in the com- putational domain,with the pressure deviation of 0. 173% and the velocity deviation of 1. 217%. The flow field pressure and its density are gradually decreased along the direction of gas flow,but it is almost unchanged in the direction of gas film thickness. The speed of flow field and pressure gradient are gradually increased along the direction of gas flow,and the speed reaches a maximum at the outlet of flow field. The temperature change in the flow field was obtained by the direct simulation method,that is the temperature change in the flow field is very little,and the overall temperature is higher on the upper and lower wall and lower in the center. While the temperature change in the flow field cannot be calculated by Reyn- olds equatio