A method for transmitting an uplink signal in an unlicensed band for a terminal configured to support multiple transmission time interval (TTI) lengths in a wireless communication system, according to one embodiment of the present invention, is performed by the terminal and may comprises the steps of: receiving a scheduling indication for multiple TTIs; according to the received scheduling indication, performing channel sensing in a clear channel assessment (CCA) gap for the multiple TTIs; and if channel sensing for at least one of the multiple TTIs is successful, transmitting, in a predetermined symbol, an uplink reference signal for the multiple TTIs.