A memory device, an operating method thereof, a system, and a non-transitory tangible storage medium are disclosed. The memory device includes a source line (SL), a bit line (BL), a memory string, a word line, a select line and a peripheral circuit. The memory string includes a memory cell and a select transistor including a storage layer. The word line is coupled to the memory cell. The select line is coupled to the select transistor. The peripheral circuit is coupled to the SL, the BL, the select line, and the word line. The peripheral circuit is configured to: apply a first voltage to the select line; and apply a second voltage to the SL and/or the BL, in which a first peak level of the first voltage is greater than a second peak level of second voltage.