We proposed a multimodal crowd counting algorithm based on RGB-Thermal (RGB-T) images (two-stream residual expansion network) in crowd counting, given scale changes, uneven pedestrian distribution, and poor imaging conditions at night. It has a front-end feature extraction network, multi-scale residual dilation convolution, and global attention modules. We used the front-end network to extract RGB and thermal features, and the dilated convolution module further extracted pedestrian feature information at different scales and used the global attention module to establish dependencies between global features. We also introduced a new multi-scale dissimilarity loss method to improve the counting performance of the network and conducted comparative experiments on the RGBT crowd counting (RGBT-CC) and DroneRGBT datasets to evaluate the method. Experimental results showed that compared with the cross-modal collaborative representation learning (CMCRL) algorithm on the RGBT-CC dataset, the grid average mean absolute error (GAME (0)) and root mean squared error (RMSE) of this algorithm are reduced by 0.8 and 3.49, respectively. On the DroneRGBT dataset, the algorithm are reduced by 0.34 and 0.17, respectively, compared to the multimodal crowd counting network (MMCCN) algorithm, indicating better counting performance.