The invention provides a portable safety seat for a military transport vehicle, which comprises a framework and a horizontal panel, wherein, the framework comprises a front support, a connection frame arranged horizontally and a back rest, and the panel is arranged on the upper end of the connection frame; the front support is hinged with the front end of the connection frame so that the front support is unlocked; the hinged position of the front support and the connection frame is equipped with at least one first locking structure, and the front support is in a vertical arrangement status when the front support is locked by the first locking structure; the back rest is hinged with the rear part of the connection frame so that the back rest is unlocked; the hinged position of the back rest and the connection frame is equipped with at least one second locking structure, and the back rest is in a vertical arrangement status when the back rest is locked by the second locking structure; and the upper end of the back rest is equipped with at least one jack catch. The seat can be assembled on a side board of a carriage flexibly so as to provide the seat for each passenger, thus the safety problem of the passenger in a car is solved; and the seat is easily folded and carried, thus saving storage space.