A method based on Vis/NIR spectral analysis technology was applied to the rapid measurement of pesticide contentration on the leaf. Near infrared spectral data of pesticide concentration on the leaf was acquired by adopting diffuse reflectance spectroscopy. Normalization of standard deviation, moving average smoothing with the segment size 3 and the first derivative combination was the optimal combination pretreatment method. From the seven schemes in contrast, the optimal hands for 350~1900nm were obtained. Partial least squares method was used to develop the quantitative analysis model for pesticide concentration with diffuse reflectance spectroscopy. The correlation coefficient between the prediction values and the truth values in the prediction set was 0.994, the root mean square error of cross-validation of the prediction set was 0.039. The result indicated that it is feasible to measure pesticide concentration on the leaf based on the near infrared (NIR) spectroscopy, and the accurate actual pesticide concentration on the leaf can be obtained after spraying pesticides.