Efficient energy-saving centrifugal fan

The utility model belongs to the technical field of ventilators, and particularly relates to an efficient energy-saving centrifugal fan which comprises a base, a motor and a volute are arranged on the base, the volute is located on one side of an output shaft of the motor, fan blades are arranged in the volute, the output shaft of the motor is connected with the fan blades, and a flow guide ring is arranged on the side face, away from the motor, of the volute. The flow guide ring comprises an annular flow guide shell, a guide vane and an angle adjusting device, the guide vane is of a fan-shaped structure, one arc-shaped side face of the guide vane is rotationally connected with the flow guide shell, the other symmetrical side face of the guide vane is connected with the angle adjusting device, and the deflection angle of the guide vane is adjusted through the angle adjusting device. The guide vane rotates to adjust the air inlet amount of the fan to adapt to the air volume change, so that the fan keeps high-e