1. A non-volatile memory device comprising: a non-volatile memory storing a plurality of data and a read table recording a plurality of indexes, wherein the different indexes correspond to different read voltages; and a controller establishing a standard table corresponding to the indexes recorded in the read table, reading a first codeword stored in the non-volatile memory corresponding to a read voltage corresponding to a first index recorded in the standard table, and executing an error check correction for the first codeword, wherein when the first codeword passes the error check correction, the controller establishes a priority table corresponding to the first index, and wherein during a next read operation, the controller reads a second codeword stored in the non-volatile memory using the read voltage corresponding to the first index recorded in the priority table and executes the error check correction for the second codeword.