Active high-lift system for short take-off and landing aircraft, comprising: - a biplane wing which comprises a main lift surface and a secondary lift surface, each one of the lift surfaces (1, 2) comprising a leading edge (1.1, 2.1), a trailing edge (1.2, 2,2), an extrados (1.3, 2.3) and an intrados (1.4, 2.4) and where: • the extrados (1.3) of the main lift surface is arranged facing the intrados (2.4) of the secondary lift surface, • the main lift surface comprises a high-lift device (1.2.2) located on the trailing edge (1.2) and comprising a surface which is curved towards the intrados (1.4) of said main lift surface along the direction of the chord of the main lift surface, • the secondary lift surface comprises a hinged flow control element (2.2.1) located on the trailing edge (2.2) and adapted to rotate around a hinging axis situated along the direction of the wingspan of the secondary lift surface, - a set of one or more motorized propulsion elements (6, 10), where each motorized propulsion element comprises a motor and a propeller and is situated above the extrados (1.3) of the main lift surface, upstream of the leading edge of the secondary lift surface so that the secondary lift surface is configured to be immersed within the wake of the propellers, characterized in that each motorized propulsion element (6, 10) is situated downstream of the leading edge (1.1) of the main lift surface. - a biplane wing which comprises a main lift surface and a secondary lift surface, each one of the lift surfaces (1, 2) comprising a leading edge (1.1, 2.1), a trailing edge (1.2, 2,2), an extrados (1.3, 2.3) and an intrados (1.4, 2.4) and where: • the extrados (1.3) of the main lift surface is arranged facing the intrados (2.4) of the secondary lift surface, • the main lift surface comprises a high-lift device (1.2.2) located on the trailing edge (1.2) and comprising a surface which is curved towards the intrados (1.4) of said main lift surface along the direction of the chord of the main lift surface, • the secondary lift surface comprises a hinged flow control element (2.2.1) located on the trailing edge (2.2) and adapted to rotate around a hinging axis situated along the direction of the wingspan of the secondary lift surface, • the extrados (1.3) of the main lift surface is arranged facing the intrados (2.4) of the secondary lift surface, • the main lift surface comprises a high-lift device (1.2.2) located on the trailing edge (1.2) and comprising a surface which is curved towards the intrados (1.4) of said main lift surface along the direction of the chord of the main lift surface, • the secondary lift surface comprises a hinged flow control element (2.2.1) located on the trailing edge (2.2) and adapted to rotate around a hinging axis situated along the direction of the wingspan of the secondary lift surface, - a set of one or more motorized propulsion elements (6, 10), where each motorized propulsion element comprises a motor and a propeller and is situated above the extrados (1.3) of the main lift surface, upstream of the leading edge of the secondary lift surface so that the secondary lift surface is configured to be immersed within the wake of the propellers,