A method of stabilizing data of digital signals is provided. The method includes steps of: setting a boundary coefficient; reading a piece of digital data; defining a value of the piece of digital data as a center value; outputting the value of the piece of digital data; reading a next piece of digital data; subtracting a value of the next piece of digital data from the previously outputted value to obtain a positive difference or a negative difference; and determining whether or not an absolute value of the positive or negative difference is larger than the boundary coefficient, if not, outputting the center value, if yes, updating the center value such that the updated center value is equal to the value of the next piece of digital data, and outputting the updated center value.