The invention discloses an impeller type washing machine and a control method thereof. The impeller type washing machine comprises an inner drum, an outer drum, an impeller and a motor. The invention further provides a control method of the impeller type washing machine. The control method can control the inner drum to rotate at a high speed when water comes into the washing machine and reaches up to a first water level, or during washing. By adopting the impeller type washing machine and the control method thereof, a liquid detergent can fully dissolve, the cleaning ratio of clothes can be raised, the operation is convenient and high in efficiency, and the effect is obvious.