The food system is a complex mega system consisting of all elements and activities related to the production, processing, distribution, preparation and consumption of food, which contributes to 34% of global greenhouse gas (GHG) emissions and has become one of the biggest drivers of global climate change. This paper adopts the literature analysis method to review recent progress in research on GHG emissions from food systems from four aspects: evaluation methods, systematic evaluation, emission reduction strategies and uncertainty analysis. This paper proposes that the accuracy of evaluation results needs to be improved in three aspects: accurate evaluation of the dietary consumption of residents in each country, improvement of the boundary of the carbon footprint accounting system, and use of regionally localized carbon footprint parameters, so as to provide a basis for the low-carbon and sustainable transformation of food systems.