The utility model discloses a retrieve device of ethane in follow natural gas belongs to the ethane field of retrieving. The the device cold box includes raw material input end, cold box and low -temperature separator intercommunication, low -temperature separator's gaseous phase output in order with expansion pressure contract expansion end, the demethanizer upper portion intercommunication of machine, and the gaseous phase output still with the first input end of cold box, demethanizer's upper portion intercommunication, low -temperature separator's liquid phase output and demethanizer's middle part intercommunication, demethanizer's gaseous phase output in order with second input, the expansion pressure of cold box machine, the product natural gas defeated system intercommunication outward that contracts, demethanizer's liquid phase output and deethanizer's middle part intercommunication, deethanizer's gaseous phase output communicates with evaporimeter, return tank in order, the gaseous phase output of return tank and gaseous phase ethane is defeated system intercommunication outward, the liquid phase output of return tank in order with fourth input, the liquid phase ethane storage facilities intercommunication of cold box, the liquid phase output of return tank still with deethanizer's top of the tower intercommunication.