In order to extract the common features about machine grading and shell breaking of different walnut, and extend the adaptability of thin skinned walnut for classification and shell breaking, for kinds of walnuts were chosen as the research objects, including 185 walnut of Xinjiang (W185), xixiang walnut of Baoshan Yunnan (XX), Yangbipao walnut of Dali (YBP), Dayao three Tai walnut of Chuxiong (DYST). Studied the differences and commonness of size, mass and compressive mechanical properties of thin walnut by basic parameter measurement and mechanical compression test. Using Excel software and Origin software to deal with the test data, the results of the study showed that: The change rule of structural characteristics and compressive mechanical properties of different walnut varieties were similar; The mechanical crushing equipment based on any kind of walnut design in the test parameters had good adaptability to the classification and crushing of the walnut walnut. The test results can provide references for different varieties of thin-skinned walnut screening and shell breaking extraction process and related crust mechanical design.