A nerve electrical stimulation device includes an electrical stimulator and a magnetic electrode assembly. The electrical stimulator includes a housing, a circuit board, two first electrical connecting elements and a first magnetic unit. One end of each first electrical connecting element is connected to the circuit board. The magnetic electrode assembly includes a main body, two electrodes, a second magnetic unit and two second electrical connecting elements. The electrodes are disposed on a surface of the main body, and connected to the circuit board. The second magnetic unit is located corresponding to the first magnetic unit. The second electrical connecting elements pass through the main body and connected to the electrodes and the other ends of the first electrical connecting elements, respectively. The magnetic electrode assembly is detachably positioned at one side of the electrical stimulator by a magnetic attraction of the first and second electrical connecting elements.
