We determine the parity check matrix and the method of the flash memory system

The present invention provides a method for determining the parity check matrix and a flash memory system. The parity check matrix comprises MxN blocks. This method includes generating a first candidate group as a candidate block of the MxN blocks in a first block set; calculating a first plurality of candidate blocks corresponding to a first set of estimation result; The estimation results of the first plurality to determine the content of the MxN blocks of the at least one first block; generating a second candidate group as a candidate block of the MxN blocks in a second block set; calculating a first block by means consider content a plurality of second candidate block corresponding to a second set of estimation result; and determined the content of the MxN blocks of the second block according to at least one of the plurality of second estimation result.