Objective To investigate the mechanistic regulatory mechanisms, phosphorylation effects and molecular structural basis of β2/FLNa interactions. Methods The crystal structures of β2/FLNa-WT and T758P complex were taken from PDB, and performed molecular dynamics simulations. The MM/PBSA method was used to calculate the binding free energy changes of the complex, and data on conformational evolution and residue interactions were analyzed. Results Following phosphorylation modification of β2 integrin THR758, the binding free energy of the complex and the pulling force accumulation were significantly decreased. The dissociation of β2/FLNa complex showed a biphasic force-dependent property under the stimulation of mechanical signals. A pure slip-bonding mechanism existed in the binding dissociation process of the complex after phosphorylation modification. Conclusions The phosphorylation would down-regulate the binding affinity of β2/FLNa complex by attenuating the M762-G2269 residue interaction, and tension would bidirectionally regulate the dissociation of the complex. The study contributes to a deeper understanding of the inflammatory response process, and provides useful references for the discovery of relevant drug targets and antibody design.