To accurately predict the air gap performance of offshore frame-type aquaculture platform, a frame-type aquaculture platform was selected as the research object. Based on linear wave diffraction/radiation theory, Morrison equation theory, and rigid body kinematics principles, frequency-domain method was employed to analyze air gap performance. The effects of viscous loads on structural slender members and nettings, disturbed wave surface elevation, position mooring system stiffness on air gap performance were analyzed. Key findings from comparative analysis include: viscous loads on structural slender members and nettings substantially improve platform motions and optimize air gap performance, with a decrease range of about 0.3-1.0 m; Disturbed wave surface elevation significantly affects the air gap performance of frame-type platforms, with an increase range of about 0.2-0.7 m and a decrease range of about 0.3-1.6 m; Position mooring system stiffness constrains platform motion and affects the air gap results, with a decrease range of about 0.1-0.4 m. The results emphasize that the effects of viscous loads on structural slender members and nettings, disturbed wave surface elevation, position mooring system stiffness should be considered reasonably in frame-type aquaculture platform air gap analysis.