A pretreatment method of a selector device is provided, which includes: (1) performing a first voltage scan of a selector through selecting a voltage scan range and setting a first limit current Icc1 to obtain a resistance state R1 of a sub-threshold region thereof; (2) setting an nth limit current Icc(n) and performing an nth voltage scan of the selector according to a resistance state Rn-1 of a sub-threshold region of the selector after an n−1th voltage scan to obtain a resistance state Rn of a sub-threshold region thereof, where, Icc(n-1)