The invention discloses a rail grinding acceptance method based on a rail grinding quality index. The rail grinding acceptance method comprise the steps that firstly, the rail profile is measured, themeasured rail profile comprises an original rail bottom slope, and then the rail grinding quality index is calculated; and the rail profile after grinding is detected by an on-board rail section detection device, the rail grinding quality index is calculated in real time by software, the difference between the rail profile and a grinding formwork is displayed, and the rail grinding quality of thesection line is given by statistics.