A CSFB-based calling method, comprising: registering to a 4G network on a base station and accessing a first cell; detecting a paging message delivered by the first cell, and redirecting to a 2G frequency point when the paging message delivered by the first cell is detected; receiving a call control message delivered by the first cell; marking the first cell as unavailable when the call control message is not connected, and switching to a second cell; and receiving a paging message delivered by the second cell. In addition, also disclosed is a CSFB-based calling device.