ObjectiveA novel sandwich electrochemical immunosensor has been developed by taking alpha-fetal protein （AFP）as the detection model, and using magnetic microspheres as the immobilized carrier of the primary AFP antibody and CdTe quantum dots as the secondary antibody label, and the performance of the immunosensor has been studied.MethodsThe primary AFP antibody immobilized immunomagnetic beads and the secondary AFP antibody immobilized CdTe quantum dots were prepared by carbodiimide crosslinking method.A novel high-sensitivity electrochemical immunosensor has been developed by sandwich immunoassay and electrochemical stripping voltammetry.In addition, the characteristics of the immunosensor were investigated by using the infrared spectroscopy, ultraviolet spectrum and electrochemical methods, respectively.ResultsThe electrochemical immunosensor exhibited a wide linear range from 1 to 200 ng/mL with a low detection limit of 0.025 ng/mL at signal to noise ratio of 3.ConclusionThis electrochemical immunosensor based on CdTe quantum dots and magnetic nanoparticles for the detection of AFP is easy, convenient, inexpensive, stable, and shows good stability and high sensitivity.