The present disclosure provides a method and a device in a first node for wireless communication. The first node first performs a monitoring on first-type signalings, in which K1 first-type signalings are detected; and then transmits a first radio signal in a first time-frequency resource set; each of the K1 first-type signalings is associated to the first time-frequency resource set; a first signaling is a last first-type signaling of the K1 first-type signaling; the first radio signal is used for determining the receiving of first-type signaling(s) associated to the first time-frequency resource set before the first signaling; or is used for determining the decoding of bit blocks scheduled by the K1 first-type signalings. With the above-mentioned designs, the present disclosure manages to address missed detection of sidelink scheduling signaling caused when a data receiver sends NACK-only feedback in V2X, thereby further improving the entire system performance.