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 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 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, 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, 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 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 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 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 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, 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, 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 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 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.