The phase transition mechanism of femtosecond laser processing metal is one of the current research hot topics.In order to have a comprehensive understanding of the current research progress of material phase transition mechanism,the researches on the interaction between femtosecond laser and metal in recent years were investigated.By comparing the research angles,methods,and conclusions of the different research teams,several theoretical models including mechanical and thermomechanical erosion,liquid phase explosion models,and vaporization and evaporation models,which are currently associated with metal phase transition,were summarized.Moreover,a summary of molecular dynamics simulation and fluid dynamics simulation methods were presented.It is found that these theories and models are only able to study and explain the material phase transition mechanism under certain specific conditions,and there is still a lack of theoretical models that can achieve cross scale(time and space dimensions)and high efficiency research.At the same time,it also gives some prospect on future research trends.