The invention discloses a clock signal quality testing method and a clock signal quality testing system based on a mobile terminal. The method comprises the steps of presetting a first threshold and a second threshold of voltage of a tested clock; generating a first interruption when the tested clock voltage is higher than the first threshold, and generating a second interruption when voltage of the tested clock is lower than the second threshold; recording the number of the first interruptions and the number of the second interruptions; and when the number of the first interruptions in a time period T is smaller than 90% of a product between frequency of the tested clock and T or the number of the second interruptions in the time period T is smaller than 90% of the product between the frequency of the tested clock and T, determining abnormity of the tested clock. The clock signal quality testing method and the clock signal quality testing system can realize real-time testing for whether the signal of the tested clock is normal after starting of the mobile terminal, and realize recording when the clock signal abnormity occurs, thereby obtaining a problem reason when breakdown or other abnormities of the mobile terminal occur, and facilitating after-sale maintenance and problem analysis of the mobile terminal.