The invention relates to a pin shaft and a contact spring device having the same. The pin shaft is installed at the bottom of a guide rod of a contact spring; and the pin shaft is perpendicular to the guide rod. A length of a cross section perpendicular to an axial direction of the pin shaft along a horizontal direction is larger than a length along a vertical direction. Therefore, mechanical reliability of the pin shaft can be improved; the fatigue life of the pin shaft is prolonged; and mechanical reliability of the contact spring pin shaft mechanism of the high-voltage vacuum circuit breaker can be improved effectively.