A pylon structure of an integrated propulsion system, which is adapted to be connected to an aircraft airfoil at one end and connected to an aero-engine at the other end, the pylon structure comprising a pylon box segment consisting of an upper beam, a lower beam, a frame and a sidewall panel, wherein the pylon structure further comprises: a thrust reverser cowl connection structure disposed on the sidewall and connected to a nacelle thrust reverser cowl comprising a front fixed cowl and a rear moveable cowl, the thrust reverser cowl connection structure comprising at least one guide rail for guiding the rear moveable cowl to enable the rear moveable cowl to slideably open relative to the pylon box segment; wherein the pylon structure further comprises a front installation joint disposed on a front wall of a front end frame of the frame and connected to a fan casing of the aero-engine; wherein the front installation joint comprises: a first lug and a second lug respectively protruding outward from two opposite sides of the front end frame; and a first link and a second link respectively connected to the first lug and the second lug at one end, and respectively adapted to be connected to the aero-engine at the other end; wherein the first link and the first lug are pivotally connected at a first connection point, and the second link and the second lug are connected respectively at a second connection point and a third connection point; wherein the pylon structure further comprises an engine duct auxiliary structure with one end connected to the pylon box segment and the other end adapted to be connected to a nacelle core cowl comprising a core front cowl and a core rear cowl, the engine duct auxiliary structure comprising a front frame hinged with the core front cowl and a rear frame connected with the core rear cowl, the rear frame being provided with at least one guide rail for guiding the core rear cowl to enable the core rear cowl to slideably open relative to the pylon box segment. a thrust reverser cowl connection structure disposed on the sidewall and connected to a nacelle thrust reverser cowl comprising a front fixed cowl and a rear moveable cowl, the thrust reverser cowl connection structure comprising at least one guide rail for guiding the rear moveable cowl to enable the rear moveable cowl to slideably open relative to the pylon box segment; wherein the pylon structure further comprises a front installation joint disposed on a front wall of a front end frame of the frame and connected to a fan casing of the aero-engine; wherein the front installation joint comprises: a first lug and a second lug respectively protruding outward from two opposite sides of the front end frame; and a first link and a second link respectively connected to the first lug and the second lug at one end, and respectively adapted to be connected to the aero-engine at the other end; a first lug and a second lug respectively protruding outward from two opposite sides of the front end frame; and a first link and a second link respectively connected to the first lug and the second lug at one end, and respectively adapted to be connected to the aero-engine at the other end; wherein the first link and the first lug are pivotally connected at a first connection point, and the second link and the second lug are connected respectively at a second connection point and a third connection point; wherein the pylon structure further comprises an engine duct auxiliary structure with one end connected to the pylon box segment and the other end adapted to be connected to a nacelle core cowl comprising a core front cowl and a core rear cowl, the engine duct auxiliary structure comprising a front frame hinged with the core front cowl and a rear frame connected with the core rear cowl, the rear frame being provided with at least one guide rail for guiding the core rear cowl to enable the core rear cowl to slideably open relative to the pylon box segment.