The invention discloses a zero oil swap energy conversion valve with double hydraulic systems and aims to provide a conversion valve capable of achieving zero oil swap of normal/emergency standby hydraulic systems in on-off conversion and switching the normal/emergency standby hydraulic systems reliably. The zero oil swap energy conversion valve is implemented by the technical scheme as follows: an unloading hole communicating a step hole of a valve cavity and an oil return check valve cavity homodromously communicating to an oil return pressure port channel are formed in a valve body; a second oil inlet connecting channel and a first oil inlet connecting channel communicate symmetrically to a second oil inlet check valve cavity oppositely to form an oil inlet loop communicating to the oilreturn pressure port channel, and two oil return check valves ejecting each other oppositely attach a valve element tightly by means of pressures of the hydraulic systems and a spring force of a valve spring; under the action of the pressures of the hydraulic systems, entrance and discharge of a normal pressure supply oil way and an emergency pressure supply oil way are separated by a seal ring arranged on a step slide valve to switch normal/emergency pressure supply oil, separately, so that on-off working states of a main hydraulic oil tank and an assistant hydraulic oil tank are controlled.