The invention relates to a method, a device and an input method system with a function of correcting an input error quickly. The device comprises an instruction module and an input method program foreground-background; and the working principle briefly comprises the steps that any character with a number is input, press keys corresponding to error characters are input, that is, the error characters are positioned quickly, and the positioned characters are corrected on various conditions. With the adoption of the method, the device and the input method system with the function of correcting the input error quickly, no matter what is the number of the error characters which are input once, whether a plurality of error characters are consecutive, and whether the characters are surplus or absent, the error character position can be quickly and directly positioned through a manner of inputting the press key corresponding to the number, and accordingly, the direct correction is achieved without deleting or correcting other correct characters. Compared with the traditional correcting method, the method, the device and the input method system are directly improved, the applicable range is wide, and great convenience can be provided for work and life of people.