Using tissue homogenate and high performance liquid chromatography(HPLC) methods, the blood-brain barrier permeability and residual tissue characteristics in were examined under different Avermectin (AVM) concentrations. AVM was detected in the 50= 0.127 mg/L, 0.071 mg/L, and 0.039 mg/L)) at 24 h, 48 h, and 96 h, respectively and the safety concentration (SC: 0.003 9 mg/L). Significant differences in the brain AVM contents among the three median lethal concentrations were observed( [() μg/g]. The above results show that AVM can penetrate the blood-brain barrier into the brain under different concentrations. Furthermore, the brain AVM contents were positively correlated with initial drug concentration. In addition, the AVM concentration-time data in the brain, liver, kidney, and muscle were all in line with the non-compartmental method in the DAS 3.0 pharmacokinetics software under the safe concentration (0.0039 mg/L). The main pharmacokinetic parameters were as follows: (1) max: liver>kidney>muscle>brain; (3) : liver>brain>kidney>muscle; (4) AUC: liver>kidney> brain>muscles. The results of this paper provide references for future fish blood-brain barrier research, and AVM nerve toxicity mechanism investigations and its application in aquaculture.