This application relates to a signal sending method, a signal processing method, and a radar apparatus, and pertains to the field of sensor technologies. The radar apparatus includes at least three transmit antennas. The signal sending method includes: determining at least two transmit antenna groups of the radar apparatus, where each transmit antenna group includes at least one transmit antenna; sending signals by using the at least two transmit antenna groups, where the at least two transmit antenna groups send signals in a TDM manner, and a plurality of transmit antennas included in each transmit antenna group including a plurality of transmit antennas in the at least two transmit antenna groups send signals in a CDM manner. Embodiments of this application may be applied to related fields such as autonomous driving, assisted driving, intelligent driving, intelligent connected vehicle, intelligent vehicle, and electric mobile/electric vehicle.