Abstract: A tripod lock device for locking a tripod having three identical legs each composed of a fixed leg and a movable leg slidably disposed between a pair of parallel spaced leg members of the fixed leg for adjusting the length of the leg in a telescopic manner. The tripod lock device is composed of three identical leg lock units each associated with one of the three legs of the tripod. Each of the leg lock units includes a frame, an eccentric cam and an engagement portion. The frame has a through-hole in which the leg members of the fixed leg and the movable leg are disposed, with one of the leg members secured to the frame. The engagement portion comprises a rod disposed on the frame at a position adjacent to said one leg member. The eccentric cam includes a presser portion and a hook.