Objective To evaluate mechanical comprehensive performance of the flexible neural electrode with coating modification, so as to provide references for optimal design of the electrode and coating parameters. Methods Simplified mechanical models were established for the contact phase, implantation phase and micromotion phase. The electrode material was polyimide, the coating material was PEG, and PDMS mold injection method was selected as the coating method. The coating thickness gradients were set as 40, 80, 120, 160 and 200 μm, respectively, and the three factors (the critical load, the maximum total deformation and the maximum strain of brain tissues) were comprehensively evaluated. Results As the thickness increased, the critical load increased, the maximum total deformation and the maximum strain of brain tissues decreased, but meanwhile, the strain area of brain tissues increased. For consideration of equilibrium for three factors, 200 μm was chosen as optimal thickness of the coating. At this thickness, the critical load was 17.9 mN, the maximum total deformation was 10.1 μm, and the maximum strain of brain tissues was 0.011 4. Conclusions The coating thickness had a great influence on mechanical properties of the neural electrode. The optimal parameters could be selected by setting influencing factors from the mechanical performance factors under specific case. The optimal parameter selection of coating can improve the electrode performance, which is of great significance for clinical application of the neural electrode.