Data processing method, memory storage device and memory control circuit unit

A data processing method, a memory storage device and a memory control circuit unit are provided. The method includes: receiving first write data; performing a first stage encoding operation of a low-density parity-check (LDPC) code on the first write data and generating first transition data; performing a second stage encoding operation of the LDPC code on the first transition data and generating a first error correcting code (ECC); receiving second write data; and performing the first stage encoding operation of the LDPC code on the second write data during a time period of performing the second stage encoding operation of the LDPC code on the first transition data. Accordingly, the data processing efficiency corresponding to the LDPC code can be improved.