The present invention discloses a touch-sensitive constant-current dimming controller used for a LED light source. The touch-sensitive constant-current dimming controller comprises a dimming controller connected between a LED constant-current driving power supply and a LED light source, and an external controller connected with the dimming controller for sending an external dimming control signal to the dimming controller, wherein the dimming controller has a first terminal connected with a positive electrode of an output terminal of the LED constant-current driving power supply, a second terminal connected with a negative electrode of an output terminal of the LED constant-current driving power supply, a third terminal connected with the negative electrode of the LED light source, and a control terminal connected with the external controller; and the dimming controller comprises a power supply circuit, a single chip micromcputer circuit, an analog-to-digital conversion circuit, a sensing touch circuit and a field effect transistor. According to the touch-sensitive constant-current dimming controller, a LED constant-current driving power supply without a dimming function can perform dimming control so as to ensure that products can meet corresponding requirements when exporting.