In order to quickly and accurately estimate stem and tiller number (STN) of winter wheat in field, the remote sensing estimation experiment of winter wheat stem and tiller number was carried out in Dafeng District of Yancheng City, Taixing City of Taizhou City and Shuyang County of Suqian City, Jiangsu Province. The red band reflectance (βred) and near infrared band reflectance (βnir) of winter wheat canopy, ratio vegetation index (RVI), normalized difference vegetation index (NDVI), differential vegetation index (DVI), shadow vegetation index (SVI), and winter wheat STN data at jointing stage were obtained. By analyzing the correlation between several remote sensing spectral indices (βred, βnir, RVI, NDVI, DVI, SVI) and winter wheat STN, the sensitive spectral indices of winter wheat STN were optimized. The BP neural network estimation model (STNBP estimation model) and the multiple linear regression estimation model (STNMLR estimation model) of winter wheat STN were established based on sensitive spectral indices, and the prediction accuracy of the models was verified. The results showed that βred, βnir, RVI, NDVI, DVI, and SVI had different degrees of correlation with winter wheat STN. The correlation coefficients ranked as βred (0.337) <βnir (0.375) < DVI (0.423) < RVI (0.446) < SVI (0.447) < NDVI (0.470), among which the RVI, NDVI, DVI and SVI were selected as the input variables to establish the STNBP and STNMLR estimation models. The model accuracy verification showed that the coefficient of determination (R2), the root mean square error (RMSE), and the average relative error (ARE) of STNBP estimation model were 0.758, 2.169×106 pieces·hm-2, and 13.7%, respectively. The R2, RMSE, and ARE of STNMLR estimation model were 0.599, 3.110×106 pieces·hm-2 and 20.0%, respectively. By comparison, the estimation effect of STNBP estimation model is better than that of STNMLR estimation model, indicating that the estimation model of winter wheat STNBP estimation model based on multiple remote sensing spectral sensitive feature index and BP neural network can effectively meet the estimation requirements of STN of winter wheat in field. |