A vacuum switch tube is provided, which includes a first conductive rod disposed with a first contact and a second conductive rod disposed with a second contact. The first contact and the second contact are disposed facing each other and sealed in a vacuum tube body. Contact bodies of the first contact and the second contact are spheres with spherical caps at two ends being cut off. The first contact and the second contact respectively include conductive members and magnetic members extending in the same direction and joining with each other to form the contact bodies. The cross section shape of the magnetic members is divided by a neutrality line into two unequal regions. The magnetic member of the first contact and the conductive member of the second contact are correspondingly disposed. The conductive member of the first contact and the magnetic member of the second contact are correspondingly disposed. The vacuum switch tube of the present invention can generate a rotating magnetic field in a vacuum gap formed between contact surfaces of two vacuum switch contacts in a vacuum arc-extinguishing chamber, so as to increase high-voltage resistant capability of the vacuum switch tube, which can be applied in a vacuum switch device of a higher voltage circuitry.