The utility model relates to the technical field of liquid dropping devices, in particular to an automatic liquid dropping device which comprises a mounting support, the mounting support comprises an upper support and a lower support, a plurality of
liquid storage tanks are arranged on the upper support, connecting covers are arranged at openings of the
liquid storage tanks, feeding pipes are arranged on the connecting covers, one ends of the feeding pipes extend into the
liquid storage tanks, and the other ends of the feeding pipes extend into the liquid storage tanks. A
peristaltic pump is arranged on the feeding
pipe, a connecting cavity is formed in the side wall of the connecting cover in the circumferential direction of the connecting cover, and a quick release
assembly used for fixing the
liquid storage tank is arranged in the connecting cavity; the upper support and the lower support are connected through a supporting plate, a fixing plate is further arranged between the upper support and the lower support, the fixing plate is connected to the lower support through a
threaded rod, a moving groove is formed in the fixing plate in the length direction of the fixing plate, and a movable mounting base used for mounting a feeding
pipe is arranged in the moving groove. When different types of liquid need to be replaced, namely different liquid storage tanks need to be replaced, the liquid storage tanks can be quickly detached from the upper bracket, so that different liquid storage tanks can be replaced.