We propose a spin valve that is based on van der Waals antiferromagnetism and is fully electrically controlled. The device is composed of two antiferromagnetic terminals that allow for vertical bias control and a linked central scattering potential region. The magnetoresistance varies significantly when the bias orientations in two terminals are switched from parallel to antiparallel, because this switch induces a mismatch of the bands for the same spin projection in different parts of the system. It is shown from density-functional calculations that bilayer graphene encapsulated by two atomic layers of Cr2Ge2Te6 provides a material platform to realize the antiferromagnetism, which is robust against the required vertical electric fields.