The invention provides a method and a device for synchronously extracting poly hydroxyalkanoate and recovering solvent from residual activated sludge with multiple impurities or various PHA-rich microorganisms through mixed culture through simple process condition at normal temperature and normal pressure. The device consists of an air blower, a dryer, a PHA chloroform solution container, a gas distribution device with gas purging, a gas connecting pipe, a tail gas exhausting pipe, an NMP absorbent container and a tail gas treatment device, wherein the air blower is connected with the drier; the drier is connected with the gas distribution device with the gas purging; the gas distribution device with the gas purging is positioned in the PHA chloroform solution container; the PHA chloroform solution container is connected with the NMP absorbent container through the gas connecting pipe; and the NMP absorbent container is connected with the tail gas treatment device through the tail gasexhausting pipe. The method and the device synchronously extract the poly hydroxyalkanoate and recover the solvent in a simple way at normal temperature and normal pressure, and have the multiple effects of simple process, environmental protection, energy conservation and the like.