A data read method for a memory storage device is provided. The data read method includes: receiving a first read command from a host system for reading first data; calculating an error bit number of the first data; and performing a correction of the first data. If the error bit number is not greater than a predetermined number, finishing the correction of the first data and returning the corrected first data at a pre-defined timing. If the error bit number is greater than a predetermined number, finishing the correction of the first data and returning the corrected first data after the pre-defined timing. In addition, a memory storage device using the data read method is also provided.