The invention relates to the technical field of electronic components, and aims at solving the technical problem that when an electric brush of the potentiometer is adjusted, adjustment is inaccurate due to ineffective contact caused by long-term friction. A tightly adjusted and controlled potentiometer provided by the invention comprises a main potentiometer body, a controller and a motor, wherein the main potentiometer body comprises an insulating bottom plate, a rotating shaft, a semi-arc resistor body and an electric brush; the rotating shaft is arranged at the centre of the insulating bottom plate; the semi-arc resistor body rotates around the rotating shaft; the electric brush comprises an electric brush base, a connection part and a contact part; the electric brush base is connected with the rotating shaft; the contact part is connected with the electric brush base through the connection part; the semi-arc resistor body is embedded into a groove which is formed by the electric brush base, the connection part and the contact part; a fastener is arranged on the connection part, and is used for adjusting the distance between the contact part and the electric brush base; the controller comprises a voice sensor, a processor and a control circuit; the motor is connected with the rotating shaft; and the control circuit is connected with the motor, so that good contact of the electric brush and the resistor body can be guaranteed, so as to realize flexible adjustment and control.