Rovibrational population transfer is controlled by a two-overlapping- pulse scheme in which the frequency ratio of the two pulses is 1:3. The calculated results show that nearly 100% of the population can be transferred from initial state |0,0to target state |3,1. The probability of population transfer can be controlled by pulse phase. When 1 =1.68 , the two pulses can be increased mutually and the probability of population transfer is also increased. When 1 =0.64 , the two pulses can be offset mutually and the probability of population transfer is reduced. The intensity of the second pulse has a significant effect on the population transfer.