The invention discloses a dual-modulus prescaler with self-adaptive dormancy, which consists of a plurality of high-speed logic units, a logic control circuit and a plurality of MOS transistors used as current sources, wherein each high-speed logic unit has a clock triggering end, a signal input end and a signal output end; the clock triggering end of each high-speed logic unit is connected with an external clock signal CLK, and the signal input end of each high-speed logic unit is connected with the output end of the logic control end; and the input end of the logic control circuit is connected with the signal output end of the high-speed logic unit and an external mode control signal. In the dual-modulus prescaler with the self-adaptive dormancy, one high-speed trigger is in the state of dormancy due to the cutting-off of the MOS transistors which are used as the current sources according to a specific digital value of a fractional frequency value and the mode control signal, so the consumption of electric energy is reduced, unnecessary waste of power consumption is avoided, and the aim of reducing the power consumption is achieved.