The present invention provides a circuit for linearly driving LED illumination based on MCU-controlled color temperature switching, comprising an SCM color temperature control module, an LED linear dimming driving and control module and an LED illumination module. The SCM color temperature control module may output two PWM signals, to adjust the ratio of current at the LED bead strings, thus to synthesize two or more different color temperatures. Or, the SCM color temperature control module outputs multi-channel control signals and then controls a color temperature output module to control the ratio of current at the LED bead strings at high and low color temperatures, thus to realize two or more color temperatures. Furthermore, a memory function or a non-memory function can be realized, if desired. The LED linear dimming driving and control module can control and adjust the illuminance of the LED illumination module, and can realize a dimming function.