The invention discloses a color temperature setting method of an intelligent dimmable LED lamp and a circuit of an intelligent dimmable LED lamp. The operation mode of a switch of a dimmer is defined,the minimum color temperature data S1, the maximum color temperature data S2, the color temperature data conversion interval, the color temperature data conversion period, the minimum brightness dataL1, the maximum brightness data L2, the maximum number of times of color temperature conversion cycles and the change corresponding relational expression of the color temperature S and the brightnessL are stored in the intelligent dimmable LED lamp. The intelligent dimmable LED lamp circuit detects and determines the duration of a zero-voltage signal input into the intelligent dimmable LED lampcircuit in real time, determines the operation mode of the switch of the dimmer in combination with the operation mode of the switch of the dimmer, and performs color temperature self-adaptive settingor changes the color temperature according to the determination result so that a user can select and can set the color temperature autonomously. The method has the advantages that the color temperature can be periodically changed within a large color temperature change range, the color temperature selection is more, and the corresponding relation between the brightness and the color temperature change is automatically updated, so that the requirement of a user on the comfort level of an illumination environment is met, and the method is convenient to use.