The utility model discloses an asphalt mixer with adjustable rotating speed, which is characterized in that a rotating screw is arranged between a top cover and an upright post, so that the top covercan move up and down on the upright post; a motor is arranged on the top cover to serve as a power source of the stirring device, a stirring shaft arranged at the bottom of the top cover is connectedwith the motor, and the motor drives the stirring shaft to stir materials in the stirring pot; the input end of the controller is connected with a temperature sensor, and the temperature sensor collects the temperature of the asphalt mixture in real time; each of the four indicator lights corresponds to one temperature range and the rotating speed range of the motor, and when the temperature of the temperature sensor is matched with the temperature range of the corresponding indicator light, the indicator light can be lightened, so that the rotating speed range of the motor at the moment can be known, and the rotating speed of the motor can be adjusted as required; the temperature of the stirred materials is collected in real time, and the rotating speed of the motor is controlled, so thatthe stirred materials are always in a controllable range.