The structure of thickener affects the aging process and service life of grease,and the key factor affecting the structure of thickener is the preparation process.In order to study the key processes that affect the structure and rheological properties of the lithium complex grease,samples were taken from each process step in the production process of the grease to observe the formation and evolution of the soap fiber structure,and to study the relationship between the structure and rheological properties of the lithium complex grease during the cooling phase and the post-treatment phase.The results show that the key step in the production process of complex lithium grease is the cooling stage.After passing the phase transition temperature,when slowly cooling to increase the dispersion time,the structure of the obtained complex lithium grease is more uniform,and the soap fiber diameter is smaller.The grease with uniform size and agent network structure has good structural stability.The post-treatment process affects the soap fiber network structure,so it is necessary to select a suitable process condition range that can fully disperse the soap particles without seriously damaging the soap fiber network structure.