For further understanding the physical mechanism of space constraints, we used the two-dimensional compressible fluid model, established dynamic simulation of laser-produced plasma under plate constraint, and calculated the evolution of the plasma process under the plate constraint. A series of time-resolved temperature distribution results obtained are basically identical with the experimental results. The mechanism of plasma temperature increase caused by the compression effect of reflected shock wave under the constraint of flat plate is revealed. The effects of different laser energies and different spacing of restraint plates on the peak temperature and the peak time of plasma temperature were also studied. The distance between the two plates increases, the peak time is obviously delayed and the enhancement effect on plasma temperature is weakened.