A device for measuring a pattern of the forces and moments (2) generated by an aircraft propulsion system (1), includes a hooking structure (5) that can support at least one propulsion system (3). This hooking structure (5) passes through the fuselage transversely relative to the main axis of the fuselage of the aircraft via an opening, whereby the structure has at least a first part (AC) that is found on the outside of the aircraft connected to a propulsion system, and a second part (CB) that is found on the inside of the aircraft that is connected to structural elements of the aircraft via an isostatic system of connecting elements (9, 10, 12, 14, 15, 22) so as to take up the six degrees of freedom, measuring elements being integrated in the connecting elements to reconstitute the pattern.