Abstract: Polydopamine (PDA) nanoparticles were prepared as a carrier, and bavachinin (BVA) was efficiently loaded by physical adsorption.The erythrocyte membrane was further utilized to modify and construct the erythrocyte membrane biomimetic nanoparticles (RBC-BP), the residence time in the body was extended and the in vivo analytical method was established to investigate their pharmacokinetics in mice.Polydopamine nanoparticles loaded with BVA (BP) were prepared by solvent replacement method, and the influencing factors of PDA loaded with BVA were investigated with the adsorption rate as the evaluation index.The erythrocyte membrane was extracted and separated, and RBC-BP was prepared by incubation coextrusion method. The effects of pH value on membrane coating and the extrusion times on the particle size and uniformity of RBC-BP were investigated.The particle size, potential, morphology, and cumulative release rate of RBC-BP were systematically characterized, and their pharmacokinetics in mice were preliminarily explored.The results showed that the adsorption rate of BP was as high as (92.08 ± 0.17) % and the drug loading rate was (42.05 ± 2.95) % at the PDA to BVA ratio of 1∶0.5, the solution pH value of 7, the incubation time of 6 h, and the incubation temperature of 20 °C, and that the erythrocyte membrane could be successfully oriented and coated on the surface of BP by the action of electric charge at the pH value of 4. The in vitro studies showed that RBC-BP has the apparent core-shell structure with the particle size of (308.63 ± 6.56) nm and good stability, and in vivo pharmacokinetic studies showed that RBC-BP can significantly extend the circulation time of nanoparticles in vivo.