For heave-preventing problem of freezing technique application, the amount of heave was compared between frozen-depth-controlled intermittent freezing mode and tranditional continuous freezing mode by experiments. The results showed that: the heave amount of intermittent mode was 48.8% that of continuous mode,and its equivalent heave amount was about 71.2% that of continuous mode,which meant frost heave was partially prevented. For heave-preventing mechanism of this intermittent mode, final ice lens was suggested as key ice lens. From qualitative analysis of experiments, heave-preventing menchanism for frozen-depth-controlled intermittent mode was indicated. Segragation temperature of final lens increased during intermittent phase for intermittent freezing mode slowed and even stopped the growth of final lens,and frost heave was thus controlled. Finally, frozen-depth-controlled intermittent freezing mode was indicated as the only applicable heave-preventing mode for engineering,and its more economic than traditional continuous freezing mode was also pointed.