The invention discloses a full-automatic quantitative packaging machine with an automatic material compensation function, and belongs to the technical field of packaging machinery. The full-automatic quantitative packaging machine comprises a frame of which the lower part is provided with a frame platform, a storage mechanism, a weighing mechanism, a weighing feed pipe, a pair of weighing feed pipe clamping mechanisms, a weighed material discharging mechanism, and a discharged material filling bag-clamping mechanism, and is characterized by also comprising a material compensation mechanism, wherein the material compensation mechanism comprises an oscillator, an oscillating discharge pipe, an adaptor pipe, an oscillating feed pipe and a material compensation hopper; the oscillator is fixedon the frame; one end of the oscillating discharge pipe is fixed on the top of the oscillator, and the other end of the oscillating discharge pipe extends towards the weighing mechanism, and is connected with one end of a material compensation pipe; the other end of the material compensation pipe is matched with the weighing mechanism; the lower end of the adaptor pipe is connected with one end of the oscillating discharge pipe; one end of the oscillating discharge pipe is matched with the upper end of the adaptor pipe, and the other end of the oscillating discharge pipe is connected with thematerial compensation hopper; and the oscillating feed pipe inclines from the material compensation hopper to the adaptor pipe. The full-automatic quantitative packaging machine has the advantages ofensuring the metering and weighing accuracy, having high work efficiency and reducing the labor intensity of workers.