The present invention discloses a method for encoding/decoding a video signal and a device for same. In particular, the method for decoding a video signal may comprise the steps of: generating a quantized transform block by carrying out entropy decoding on the video signal; generating an inversely quantized transform block by carrying out inverse quantization on the quantized transform block; determining whether or not to apply a secondary inverse transform on the basis of information related to a non-zero coefficient in the inversely quantized transform block; and carrying out a secondary inverse transform on the inversely quantized transform block by using a secondary inverse transform kernel applicable to the inversely quantized transform block.