The invention discloses an aging power supply device with parallel input and series output and belongs to the field of power electronic system control. The device is mainly composed of a host, a slave, a power supply module, a load device, a display panel, a control panel, a first fan, a second fan, a first thermistor and a second thermistor module, wherein the host is connected with an input endof the slave in parallel, the host is then connected with a power grid of the power supply module, the output of the host and the output of the slave are connected in series and then connected with the load device, and the outputs are connected in series and then connected with the load device as an output end of the aging power supply device, and thereby input-parallel output-series is realized.The aging power supply device is advantaged in that internal topological structures of the host and the slave are the same, the internal topological structures of the host and the slave respectively comprise three control circuits including a single-phase AC / DC converter circuit, an isolation LLC resonant converter circuit and a bidirectional BUCK-BOOST converter circuit, energy can flow in two directions, a power grid is not polluted, loss is small, cost is low, and reliability and practicability are good.