The function of audio-visual records system of interrogation in China has been restricted artificially, which is essentially regarded as a self-discipline tool for the investigation organ. The ostensible purpose of audio-video recording is to prevent torture, while the deep purpose aims at preventing misjudged cases caused by false confession. The orientation as self-discipline tool makes audio-video recording weak in regulation on various factors which may cause misjudged case; in the meantime, its function dissimilate from“power control”to“power guarantee”in practice, which forms logical paradox. Audio-video recording has the potential of becoming the best evidence to prove interrogation matters. We should treat the prevention of false confession as its core purpose and transform its function to litigation evidence. To make audio-video recording become best evidence, the following problems should be solved: moderate legalization of collecting the defendant's states by seducing or cheating; treating the synchronized audio-video recordings differently in different types of cases; differentiation in transferring with the cases; ensuring that the defense can use the audios and videos conveniently; promoting the synchronized audio-video recording and transferring with the cases by advancing system.