The electrochemical immunosensor was fabricated by immobilizing alpha-fetoprotein (AFP) antigen onto the magnetic glassy carbon electrode (MGCE) that modified by Fe3O4@polystyrene (PS)/polydopamine (PDA)-Au nanotubes. The aim of this study was to develop a new route to prepare Fe3O4@PS/PDA-Au nanotubes with well dispersed Au nanoparticles (AuNPs). The immune detection platform showed good analytical performance for determination AFP in a linear range of 0.01-100 ng/mL with a correlation coefficient of 0.9970 under optimal conditions. The detection limit was calculated to 0.0088 ng/mL (S/N = 3). In addition, the good detection results of AFP in human serum were obtained by the immunosensor. The use of composite nanotubes to build advanced biosensing interface will bring more possibilities for future biomedical detection.