A quantitative analysis model for silage ferment quality of corn ensile is established by using the near infrared spectroscopy. The detection result of the near infrared model established for organic acid and ammoniacal nitrogen is better than that of the near infrared model established for six ferment products such as lactic acid and acetic acid. The near infrared model established for organic acid and ammoniacal nitrogen has a prediction correlation coefficient of 0.8453 and a mean difference of 10.3582. Its judgment accuracy for silage quality is 80.15 %. The experimental result shows that the near infrared spectroscopy can be used to quantitatively analyze the organic acid and ammoniacal nitrogen content of corn ensile and is expected to be a rapid detection tool for the silage ferment quality of corn ensile.