In order to better control the flexographic printing pressure, the pressure in the printing process was measured by installation of a thin pressure sensor in central area of the pressure. The pressure calculation model in flexographic printing was established based on the measurement and the required maximum printing pressure for the best flexographic printing quality was obtained. The relation between the maximum printing pressure and the hardness of printing plate was analyzed through experiments. The purpose was to provide reference for printing pressure selection for printing plate of different hardness.