A computer with an anti-lost cigarette lighter includes a computer and a cigarette lighter disposed on a computer mainframe box. The cigarette lighter is equipped with a lock cylinder that is mounted so as to be movable and held at a cigarette lighter unlock position or cigarette lighter lock position. The invention provides the computer with the cigarette lighter, so that a cigarette can be easily lit at any time when a user needs, without an open flame, and the safety is high. Since the lock cylinder is originally used, when a plug of the cigarette lighter is plugged and clamped into a socket of the cigarette lighter, by moving and holding the lock cylinder at the cigarette lighter lock position, a clamping end of an elastic card in the socket of the cigarette lighter can be prevented from being deformed outwards via an elastic card deformation opening, so that the plug of the cigarette lighter is prevented from being pulled out. In this case, if the cigarette lighter is not unlocked in advance, the plug of the cigarette lighter cannot be pulled out simply by forcibly pulling the plug of the cigarette lighter, and relatively, the function of preventing the plug of the cigarette lighter from being lost is effectively realized.