An unavoidable disadvantage of most traditional sampling methods is the large amount of samples data preservation during sampling process. Equivalent Time Sampling is a popular sampling method which usually used in oscilloscope technology. When input signals have the similar features as the jump signal, whose information focus in a very short period of time, the Equivalent Time Sampling’s disadvantage will become more obvious. This paper proposed a new sampling method named Vertical Sampling based on testing time via ADC. High-speed voltage comparator, ADC, and mathematical model between phase and time are used in this method. The whole system obtains unknown input signal’s tendency information and the time difference information to accomplish the sampling process. Experimental results proved this new method’s effectiveness on reducing the samples for three kinds of signals especially for the jump signals.