A method for improving readability of an optical disc includes: changing a first control parameter of an optical storage apparatus that accesses the optical disc and obtaining a plurality of associated values of an index corresponding to the readability of the optical disc for respective changed/unchanged values of the first control parameter; setting the first control parameter to be an optimal value out of the changed/unchanged values of the first control parameter according to the index; changing a second control parameter with the first parameter set to be the optimal value to obtaining a plurality of associated values of the index for respective changed/unchanged values of the second control parameter; and setting the second control parameter to be an optimal value according to the index. The control parameters having their individual optimal values are utilized for further control during decoding. In addition, an associated optical storage apparatus is further provided.