Abstract: An integrated pressure condensing boiler is provided which relates to the technical field of boilers. The integrated pressure condensing boiler includes a pressure-bearing housing, a heat-exchange furnace arranged in the pressure-bearing housing, a combustion chamber communicating with the heat-exchange furnace and cooling tube groups fixed in the heat-exchange furnace. Heat-exchange medium flows from bottom to top in the pressure-bearing housing and in the cooling tube groups, and exchanges heat with high-temperature flue gas flowing from top to bottom in the heat-exchange furnace, thus achieving a counterflow heat exchanging. The heat-exchange furnace includes a multi-stage heat-exchange chamber with each heat-exchange chamber being cylindrical. The heat-exchange chambers are arranged in sequence from top to bottom to achieve a flue gas diffusing manner that high-temperature flue gas diffuses from center part to periphery and then gathers from periphery to center part.