In order to rapidly and accurately acquire cucumber growing information, such as the nitrogen content and leaf area index (LAI), a multi-spectral imaging technique was investigated. The linear relation between reflectance and image gray value was developed using the calibration board. The gray value of leaf sample was achieved by image processing of green, red and near infrared channels obtained by a three-channel CCD camera. Then the gray value of the leaf sample was transferred into reflectance value by aforementioned experiential linear function. The reflectance value was used for the calculation of vegetation index. Least squares-support vector machines (LS-SVM) model was developed for the relation between vegetation index and nitrogen content, vegetation index and leaf area index. The results indicate that the correlation coefficients of vegetation index and nitrogen content, vegetation index and LAI are 0.8665 and 0.8553, respectively. The overall results demonstrate that there is a close relation between the vegetation index and growing information of cucumber, and the multi-spectral imaging technique is a new powerful method for the acquisition of cucumber growing information.