The invention relates to a time-display instant switching mechanism which comprises a unit escapement fork, a second wheel, a unit case, a unit escapement wheel, a unit hair spring and a unit gear. The unit case, the unit escapement wheel, the unit hair spring and the unit gear are coaxially arranged, the unit case and the unit escapement wheel are coaxially connected, a gap is reserved between a revolving shaft of the unit gear and a revolving shaft of the unit case, one end of the unit hair spring is connected with the unit escapement wheel, the other end of the unit hair spring is connected with the unit gear, the unit escapement fork is arranged beside the unit escapement wheel, and the second wheel is meshed with a second wheel tooth on a watch and with the unit gear, and is arranged on a poking nail capable of contacting the unit escapement fork during the rotation. Since the hair spring is used for storing energy and combined with an escapement mechanism to achieve instant switching of time display, energy transferred to a balance wheel by a gear driving system is guaranteed against reduction, and travel time precision of a mechanical timekeeper is increased. The time-display instant switching mechanism is small in energy consumption, convenient to achieve and high in reliability, and satisfies the requirement of mass production.