A method for performing garbage collection (GC) management of a memory device with aid of block classification and associated apparatus are provided. The method may include: utilizing a memory controller to divide at least one portion of blocks among a plurality of blocks into multiple first blocks belonging to at least one first type in a first area and multiple second blocks belonging to at least one second type in a second area; utilizing the memory controller to receive a first command from a host device through a transmission interface circuit within the memory controller; and during writing data in response to the first command, performing a foreground GC procedure to control the memory device to perform GC before completing at least one writing operation corresponding to the first command, for controlling priority of releasing storage space of the second area to be higher than that of the first area.