A retiming circuit module, a signal transmission system, and a signal transmission method are provided. The retiming circuit module includes a path control circuit and a multipath signal transmission circuit. The multipath signal transmission circuit includes built-in first signal transmission path and second signal transmission path. The multipath signal transmission circuit may perform first signal transmission between an upstream device and a downstream device based on a first signal transmission frequency and the second signal transmission path. During a period of performing the first signal transmission, the path control circuit may detect a first data sequence transmitted between the upstream device and the downstream device. The path control circuit may control the multipath signal transmission circuit to switch to perform second signal transmission between the upstream device and the downstream device based on the first signal transmission frequency and the first signal transmission path according to the first data sequence.