The invention relates to an amount recognition system for code scanning payment cash register of merchants, and an implementation method of the amount recognition system. The amount recognition system is characterized in that: original cash register software of merchants does not need to be modified, and code scanning payment cash register software is additionally installed to achieve support for code scanning payment; when the code scanning payment cash register software is installed for the first time, a screenshot region in the cash register software is set by using a button (1) marked with ''selecting amount appearing region'', the code scanning payment cash register software automatically performs screenshot on a settlement amount region of the cash register software according to a preset range when carrying out code scanning payment settlement each time, an opencv computer vision library is used for performing preprocessing on a picture to generate a binary image and save it, then a specific amount is recognized and amount input is automatically achieved through OCR (optical character recognition) according to a language package which is specially trained and corrected.