A fan assembly for a robot vacuum cleaner and a robot vacuum cleaner are provided. The fan assembly includes an electric motor, a stator impeller, a rotor impeller and a fan cover. The stator impeller defines a shaft hole, the electric motor is mounted on a side of the stator impeller, and an output shaft of the electric motor passes through the shaft hole. The fan cover is mounted on another side of the stator impeller, and an end surface of the fan cover away from the stator impeller defines an air inlet. The rotor impeller is mounted to the output shaft of the electric motor and located between the fan cover and the stator impeller.