The invention relates to a full-automatic filling machine indexing mechanism. The mechanism comprises a power device, an indexing device and a mounting rack, wherein the power device is fixed on a bottom plate of the mounting rack through a fixing pin roll on the mounting rack, an indexing shaft of the indexing device is fixedly installed on an indexing center hole of the bottom plate through a bottom plate bearing seat, a push plate of the power device is connected with the indexing shaft of the indexing device through a bearing, three pawls of the indexing device are respectively connected with pawl shafts fixed on a cushion plate and the bottom plate of the mounting rack in a sliding mode, the three pawls respectively lock an indexing wheel, and the indexing shaft is connected with a star wheel shaft on a filling machine through a coupler. The full-automatic filling machine indexing mechanism is low in manufacturing cost, simple in structure and strong in generality, angles can be accurately adjusted in forward and reverse directions according to the needs, the push plate is driven to rotate around the indexing shaft through an air cylinder, an indexing operation is completed through intermittent fixing of the three pawls and the rotation of the indexing wheel, and the full-automatic filling machine indexing mechanism has the advantages of being high in indexing precision, easy and convenient to operate and the like.