We propose a new idea to measure the temporal contrast of laser pulses in this paper. Unlike the traditional time-to-space transformation method, the design in this paper can be called a somewhat time-to-time transformation. A single-shot pulse beam is simultaneously divided into two separate beams by a beam splitter. The two beams then enter a pair of optical replicators respectively to generate two pulse sequences that have equal time intervals respectively. The time interval of the two sequences alters by about 100fs that we can use one sequence to scan the other at a time resolution of 100fs through a nonlinear crystal. The time resolution depends on the altering of time interval and the time window depends on the pulse number of the sequence. This method can avoid the spatial modulation of the laser pulse. On the other side, the time resolution and time window are adjustable. It is also possible to measure the high contrast with a low-dynamic- range detector by attenuating the power of each pulse in the sequence respectively.