On the basis of analyzing the anti-collision principle of the correlation inter-digital transducer (CIDT), by using correlation function and taking the autocorrelation and cross-correlation characteristics of the codes as indicators, two sets of phase codes which respectively containing eight sequences were obtained from the search through the pseudo-random code Gold sequences and Walsh sequences. The δ function model of the CIDT was established to simulate its transfer function and the surface acoustic wave response signals of the CIDTs encoded by the two sets of phase codes were analyzed. The research shows that the CIDTs encoded by Walsh sequences have better anti-collision performance, which indicates that the cross-correlation of codes plays a more critical role in anti-collision performance compared with the autocorrelation codes.