The invention relates to the field of medical sanitary equipment and discloses an automatic sample feeding device. The automatic sample feeding device comprises a sample separating device, a uniform mixing device arranged below the sample separating device and a discharge device arranged below the uniform mixing device, wherein the sample separating device is used for separating an independent test tube row from a plurality of sample storage test tube rows, the independent test tube row falls into the uniform mixing device and is subjected to uniform mixing, and the test tube row falls into the discharge device from the uniform mixing device and is subjected to discharge operation. According to the automatic sample feeding device, steps including separation, uniform mixing-puncturing, discharging and the like of the test tube rows can be automatically finished in the vertical direction, the device is compact in structure and occupies small space, the motion displacement of the test tube rows is shorter, and time shortening and efficiency increase are facilitated; by means of the sample separating device, multiple test tube rows can be added once, and work load of feeding is reduced.