In the context of multi-tap self-interference cancellation in the multipath channel in the Co-time Co- frequency Full Duplex (CCFD) system, the current studies focus on the experimental verification technologies in the RF-domain self-interference cancellation. The lack of performance analysis of multi-tap settings, amplitude, and phase on the self-interference is not conducive to the selection of engineering parameters. In the conditions of particular tap number and delay, this study gives the derivations for amplitude and phase of each tap, and also the influence of amplitude and phase error on the self-interference cancellation. Both the analysis and simulation show that firstly, for a specific number of taps, when the max tap delay is less than the delay of the main path of self-interference, the self-interference cancellation value is increased with the increase of the max tap delay, while the max tap delay is about two times larger than the delay of the main path of self-interference, the self-interference cancellation value decreases with the increasing of the max tap delay; secondly, for the particular tap delay coverage, when the tap number is increased or the bandwidth of self-interference signal is reduced, the self-interference cancellation value increases; thirdly, for the specific the tap number and delay setting, with the increase of amplitude or phase error, the self-interference cancellation value is more and more small.