Provided is a method for processing a video signal on the basis of an arbitrary partition transform, the method comprising the steps of: determining a partition set for input data, the partition set indicating a set of partitions divided from a data block on the basis of a scanning pattern; determining a transform matrix set corresponding to the partition set; obtaining an arbitrary partition transform vector for each partition by applying the transform matrix set to the partition set; and obtaining the arbitrary partition transform coefficient for the input data by inverse-mapping the arbitrary partition transform vector.