A memory card and a non-volatile memory controller thereof are provided. The non-volatile memory controller includes a firmware download port group, a memory interface unit, a processing unit, and a host interface unit. The firmware download port group is used for coupled to a firmware update fixture. The memory interface unit includes at least one tri-state buffer component, and the memory interface unit is coupled to a non-volatile memory and the firmware download port group through the tri-state buffer component, wherein the tri-state buffer component determines whether to operate in a high-impedance mode or a normal mode according to a mode single. The processing unit accesses the non-volatile memory through the memory interface unit. When the tri-state buffer component operates in the high-impedance mode according to the mode single, the firmware update fixture writes a new firmware into the non-volatile memory through the firmware download port group.