The invention relates to a plug-in coupling for the transfer of high-power energy and for the transfer of a fluid under pressure, consisting of at least one coupler plug (2) and at least one coupler socket (3). The coupler plug (2) can be introduced into the coupler socket (3) at least to some extent to produce a coupled state and can be removed from the coupler socket (3) to produce a decoupled state. The coupler socket (3) and the coupler plug (2) advantageously comprise an inner conductor (4, 5) which is electroconductive in at least some sections and which is surrounded by a fluid channel (6) in at least some sections. The coupler socket (3) and the coupler plug (2) have means (7, 8) for sealing the fluid channel (6) in a liquid-tight manner in the decoupled state and for producing a continuous fluid channel (6) in the coupled state.