The invention relates to a low power consumption frequency modulation method based on a time slice utilization rate. According to the technical scheme, the method comprises steps as follows: step one, a multitask model is established; step two, expected utilization rates of tasks are calculated; step three, a mapping between the processor frequency and a processor utilization rate is established; and step four, frequency modulation is performed on a processor during task execution. The low power consumption frequency modulation method is applicable to a system based on time slice scheduling, the time continuity characteristic of the same task or the same kind of tasks on the processor utilization rate is fully utilized, the scheduling speed is increased, the power consumption for task operation is reduced, and the overall performance of task scheduling is improved.