A time-interweaved sampling scheme for analog-to-digital (A/D) conversion based on mode-locked-pulse and high-speed optical switch is proposed. The radio frequency (RF) signal is sampled by high repetition rate ultra-short mode-locked pulse, and then demuxed by high-speed optical switch, which can convert the high frequency sampled signal to multi-channel lower frequency signal. So we can use electronic A/D conversion to quantize and code. The frequency of signal demuxed by optical switch can change easily if the frequency of the optical switch is changed. This scheme is very flexible, and only one mode-locked-laser is required. The scheme is demonstrated using a mode-locked-pulse with repetition frequency of 10 GHz and a 1.25 GHz high-speed switch. Using the experimental data, a better in-time signal is recovered and the spectra is obtained. The signal-to-noise of this scheme is 32.02 dB, equivalent to effective number of bits of 5.03 bit.