Example signal reconstructing method and apparatus are described. One example method includes obtaining a reference sound channel and a target sound channel. An adaptive length of a transition segment is obtained based on an inter-channel time difference in the current frame and an initial length of the transition segment. A transition window in the current frame is obtained based on the adaptive length of the transition segment. A gain modification factor of a reconstructed signal is obtained. A transition segment signal on the target sound channel is obtained based on the inter-channel time difference, the adaptive length of the transition segment, the transition window, the gain modification factor, and a reference sound channel signal and a target sound channel signal.