The galvanic corrosion and electrical insulation between TC4 Ti-alloy and 304 stainless steel coupled in pipe joints were investigated using the finite element method. The results obtained from polarization were applied as boundary conditions. The simulation incorporated secondary current distribution with chemical species transport and laminar flow. COMSOL modeling provided calculated values that showed good agreement with experimental measurements. The model was utilized to examine the influence of geometric and environmental factors, including insulation resistance, insulation distance, pipe diameter, temperature, and electrolyte concentration, on the galvanic corrosion process. The results indicated that electrical insulation performance significantly affects the corrosion process.