In order to investigate the change law of the interface behavior between the biomimetic mucus hyaluronic acid system and the water phase with time,the change of the molecules at the biomimetic mucus water interface was studied through molecular dynamics research by using the Nose extended system temperature control method,Atom based calculation method and Ewald calculation method combined with the forcite module.Taking the aqueous solution of hyaluronic acid as a representative,the interfacial stability was discussed from the microscopic level by simulating biological mucus.The factors affecting the interfacial stability were analyzed from the aspects of interfacial tension,interfacial interaction energy,radial distribution function and root mean square displacement.The results show that when the mass ratio of hyaluronic acid polymer polymer and water molecule is 1∶10,the minimum interfacial tension is 61.33 mN/m,the unit interfacial energy is 242.67 kJ/(mol·nm2),and the interface is the most stable.According to MSD curve and RDF (radial distribution function),the interaction between water molecules and hyaluronic acid molecules and the movement of water molecules also indirectly indicate that the interfacial stability of the system is the highest when the mass ratio is 1∶10.The simulation results are consistent with the experimental stability results,and some rules of the interface between hyaluronic acid system and water are explained from the microscopic level.