Decoding method, memory control circuit unit and memory storage device

A decoding method, a memory control circuit unit, and a memory storage device are provided. The method includes: configuring a plurality of read voltage categories, wherein the read voltage categories respectively have a plurality of representative read voltage sets; reading a first physical programming unit according to the representative read voltage sets and executing a decoding operation to obtain a plurality of decoded information; choosing a first read voltage category according to the plurality of decoded information; and reading the first physical programming unit according to the first read voltage sets in the first read voltage category and executing the decoding operation.