The invention relates to the field of image understanding, discloses an image description generation system and method based on a weighing attention mechanism, and solves the problems that an existingimage description scheme lacks a polishing process, the training process and the testing process are inconsistent, and the generation description recognition degree is not high. The method comprisesthe following steps: a, processing a data set: extracting global features and local features of an image, constructing the data set, marking words in the data set, and generating corresponding word embedding vectors; B, training an image description generation model: generating rough image description by adopting a first layer of decoder based on a residual attention mechanism, and carrying out polishing on the generated image description by adopting a second layer of decoder based on the residual attention mechanism; And c, further training the model in combination with reinforcement learning: simulating a test process of the model in the training process, guiding the training of the model by generating a described CIDEr score, and adjusting the model in combination with reinforcement learning.