The invention relates to a pressure loading and maintaining transport system and a pressure loading and maintaining transport method of a decorative sheet for a building. The phenomenon that the production of sheets is over high and the sheet laminating and bonding speed lags behind is avoided; the whole stack of sheets are conveyed to a cold press for pressing at a time; the cold press and a production line are combined into a whole; a pressure maintaining procedure is finished during transportation; during use, the whole stack of sheets are unloaded and the pressure maintaining time is finished; an original pressure maintaining procedure in a workshop is transferred to the transportation process; equipment elements are standard accessories and can be relatedly used for multiple times, so that the working efficiency of producing a finished product of the sheet is greatly improved, the production period of the finished sheet is shortened, and the operation efficiency of equipment matching is improved; meanwhile, the occupied area of a factory building of a production side is reduced and the production cost is reduced; high-efficiency delivery services are provided for exterior wall components of an expressway needing quick construction, the demand of delivering customized goods in a short time can be met, and the integral construction time is shortened.