The invention discloses a picture description generation method and system based on an Actor-Critic generative adversarial network, and the method comprises the following steps: (1) obtaining a picture described by a known text, carrying out the preprocessing, and constructing a training set, (2) establishing a target network based on a generative adversarial network and an Actor-Critic algorithm,wherein the target network comprises a generator network, a discriminator network and a Critic network, (3) inputting the pictures in the training set and the text description of the pictures into the target network, performing pre-training and adversarial training on the generator and the discriminator, and performing single-step updating on the parameters of the generator by adopting an Actor-Critic algorithm, and (4) inputting the target picture needing to generate the text description into the trained generator to obtain the text description of the target picture. According to the method,based on the Actor-Critic algorithm, an adversarial network technology is adopted, and diversified text description can be generated on a given image.