A memory device and an operation method thereof are provided. The memory device comprises: a memory array; a decoding circuit coupled to the memory array, the decoding circuit including a plurality of first transistors, a plurality of second transistors and a plurality of inverters, the first transistors and the second transistors are paired; and a controller coupled to the decoding circuit, wherein the paired first transistors and the paired second transistors are respectively coupled to a corresponding one inverter among the inverters, and respectively coupled to a corresponding one among a plurality of local bit lines or a corresponding one among a plurality of local source lines; the first transistors are coupled to a global bit line; and the second transistors are coupled to a global source line.