Disclosed are a video signal processing method and apparatus for encoding or decoding a video signal. In more detail, the video signal processing method includes receiving intra prediction mode information for a current block, wherein the intra prediction mode information indicates one of a plurality of intra prediction modes configuring an intra prediction mode set; and decoding the current block based on the received intra prediction mode information, wherein the intra prediction mode set comprises a plurality of angle modes, and the plurality of angle modes comprises a basic angle mode and an extended angle mode, wherein the extended angle mode is signaled based on the basic angle mode.