The invention provides a method and system for improving the memory access efficiency in a multi-core processor, comprising the following steps of matrix block mapping: dividing a matrix into a plurality of sub-matrices, and storing each sub-matrix in a page of a DDR memory respectively; carrying out the multi-core concurrent access of accessing the sub-matrices in DDR memory simultaneously through multiple cores. The invention equalizes the row and column data access rates; reduces the contention for concurrent access to multiple cores and has the good universality.