  Diffusion models have become a powerful family of deep generative models,
with record-breaking performance in many applications. This paper first gives
an overview and derivation of the basic theory of diffusion models, then
reviews the research results of diffusion models in the field of natural
language processing, from text generation, text-driven image generation and
other four aspects, and analyzes and summarizes the relevant literature
materials sorted out, and finally records the experience and feelings of this
topic literature review research.
