The invention relates to a dimmer and dimmer control circuit. The dimmer control circuit comprises: three-end bidirectional controllable silicon switch element, comprising grid and turned on by trigger signal of the grid, connecting to AC power supply through lamp load; and a first variable resistor, possessing adjustable resistance and regulating lamp brightness by following modes: changing resistance value of the first variable resistor, changing phase of the trigger signal corresponding to AC voltage waveform, prolonging or shortening turning-on time bucket of three-end bidirectional controllable silicon switch element, thereby changing current provided to the lamp load. The dimmer control circuit also comprises a second variable resistor, for changing phase of trigger signal independent of the first variable resistor.