Method for determining at least one minimum power margin of a hybrid drive train for a transport vehicle, in particular an aircraft, the drive train comprising a plurality of power sources of different natures, a plurality of power consumers and a plurality of drive elements (H1-H4), each drive element (H1-H4) being associated with at least one power source and at least one power consumer, the method comprising: - a step of acquiring (ET1) measurements (Pv) of a plurality of power parameters (PARi) of the hybrid drive train , at least two measurements (Pv) being expressed according to different magnitudes. - a step of comparing (ET2) each measurement (Pv) with at least one limitation threshold (Pseuil), determined respectively for each power parameter (PARi) from a threshold database (DB_SEUIL), in order to deduce therefrom at least one gross power margin (Pmb) for said power parameter (PARi), - a step of converting (ET3), from a transformation database (DB_TRANS), the gross power margins (Pmb) of said power parameters (PARi) into refined power margins (Pma) expressed according to the same common magnitude, - a step of transposing (ET4), from a yield database (DB_REND), refined power margins (Pma) into standardized power margins (Pmn) at at least one reference point of the hybrid drive train , the yield database (DB_REND) determining the yields of the transmission member between an acquisition point and a reference point, - a step of determining (ET5) a source power margin (MIndS), from the standardized power margins (Pmn) of the sources at said reference point, and a consumer power margin (MIndC), from the standardized power margins (Pmn) of the consumers at said reference point. - a step of determining (ET6) the minimum power margin (Mind) by selecting the lowest power margin between the consumer power margin (MlndC) and the source power margin (MIndS) at said reference point. - a step of acquiring (ET1) measurements (Pv) of a plurality of power parameters (PARi) of the hybrid drive train , at least two measurements (Pv) being expressed according to different magnitudes. - a step of comparing (ET2) each measurement (Pv) with at least one limitation threshold (Pseuil), determined respectively for each power parameter (PARi) from a threshold database (DB_SEUIL), in order to deduce therefrom at least one gross power margin (Pmb) for said power parameter (PARi), - a step of converting (ET3), from a transformation database (DB_TRANS), the gross power margins (Pmb) of said power parameters (PARi) into refined power margins (Pma) expressed according to the same common magnitude, - a step of transposing (ET4), from a yield database (DB_REND), refined power margins (Pma) into standardized power margins (Pmn) at at least one reference point of the hybrid drive train , the yield database (DB_REND) determining the yields of the transmission member between an acquisition point and a reference point, - a step of determining (ET5) a source power margin (MIndS), from the standardized power margins (Pmn) of the sources at said reference point, and a consumer power margin (MIndC), from the standardized power margins (Pmn) of the consumers at said reference point. - a step of determining (ET6) the minimum power margin (Mind) by selecting the lowest power margin between the consumer power margin (MlndC) and the source power margin (MIndS) at said reference point. <EOS>