To evaluate the in vitro release rate and antibacterial efficacy of cefquinome sulfate suspension.This study used a simulated in vitro physiological equilibrium system and high-performance liquid chromatography(HPLC) to detect and analyze the in vivo release of the formulation.The method of mixing the drug with various bacteria and culturing them was used to analyze the bactericidal and bacteriostatic times and effects of the drug.The results showed that the in vitro release rate was ranked in the order of fastest to slowest:kw5>kw1>kw3>kw2>kw7>kw8>kw6>kw4.It was found that kw1 had a moderate bactericidal speed,but its duration was longer,and it could still prevent bacterial resistance from developing for 72 h.The results showed that cefquinome sulfate suspension has good antibacterial efficacy and can maintain its effect for a long time.Therefore,it is suggested for clinical application.