An anti-lost device for infants in an amusement park comprises a management center (1), wherein each assembly comprises a primary watch (2) with a watch structure and a plurality of secondary watches (3), the primary watches (2) and the secondary watches (3) are all provided with positioning chips (4), and direction information of each positioning watch can be known through the management center; the primary watch (2) of each assembly can be communicated with the corresponding secondary watches (3) through a corresponding built-in communication module (5). After being worn and locked, the primary watch (2) and the secondary watches (3) of each assembly can be taken off only through a special key; the primary watch (2) and the secondary watches (3) of each assembly can send out a prompt message through remote control, so that the infants can be conveniently looked for when getting lost; the prompt message is sent out through sound or is displayed through LED (light-emitting diode) light; accurate positions of related people can be dynamically monitored, and the infants can be quickly looked for when getting lost and can be prevented from being abducted.