Word line control method and erasing method for flash memory

The invention discloses a word line control method and an erasing method for a flash memory. The word line control method comprises the following steps of: applying a first positive voltage to a word line at the time between a first moment and a second moment, wherein the second moment lags behind the first moment; applying a second positive voltage to the word line at the time between the second moment and a third moment, wherein the third moment lags behind the second moment, the second positive voltage is higher than the first positive voltage, and the time between the second moment and the third moment accounts for 10%-20% of the time between the first moment and the third moment. According to the word line control method and the erasing method provided by the technical scheme of the invention, the degradation speed of a tunnel oxide layer in the flash memory can be reduced and the durability of the flash memory can be improved.