A multi-channel continuous photonic time-stretched analog-to-digital converter (PTS-ADC) system based on the time and wavelength interweaved technology is designed. And the effect of complementary dual Mach-Zehnder modulator (MZM) structure on PTS-ADC is studied. The principle of complementary dual-MZM which can suppress second-order harmonic in PTS-ADC is verified by theoretical deduction. A continuous PTS-ADC system based on complementary dual-MZM is designed. We simulate the analog to digital conversion of 6 GHz radio frequency (RF) signal by Optisystem. The simulational results show that the system can realize the down-conversion processing and continuous sampling of the RF signal, and the effective number of bits (ENOB) of 4.69 is achieved.