To characterize plant wilting status, a laser scanner based on triangulation principle was used to obtain 3-D images of zucchini. Four wilting indices (TB_3D, RLWI-2DFT, RTPLA, RS) were developed by using different mathematic methods (differential geometry, 2D Fourier transform, top projected area, standard deviation) to identify the plant wilting. It was observed that the indices were capable of sensing the stress response of zucchini from slight wilting to severe stress levels. Regression results showed that TB_3D had a linear relationship with ambient temperature and global radiation, the decision coefficient were [0.710, 0.721] and [0.513, 0.589], respectively. Besides, TB_3D was also found to be linearly correlated with stem diameter, and R2 was 0.845. Additionally, the correlations of wilting series characterizing by these four wilting indices were analyzed respectively. The R2 of each two indices was larger than 0.736. The results showed that the four wilting indices had the similar effects.