Time delay and integration (TDI) in digital domain with the complementary metal-oxide-semiconductor (CMOS) sensor has low cost, low power consumption, flexible operation and other advantages, it has attracted much research attention in recent years. However, the rolling shutter of the CMOS sensor produces distortion for imaging on moving object. In order to study the impact of the rolling shutter on TDI in digital domain, the mathematical model of image motion and modulation transfer function (MTF) decline induced by the rolling shutter effect on TDI in digital domain is established, combining with the principle of the rolling shutter. And the estimation analysis and confirmatory experiment are carried out combining with the derivation model. The results show that the rolling shutter bring a large affect on TDI in digital domain; the image motion gets larger and MTF declines more serious as the readout time gets longer; in addition, the influence gets more serious as the line period gets shorter, when the line period goes from 200 us to 100 us, the corresponding MTF of the images generated by TDI in digital domain decreases from 0.6144 to 0.4807.