Abstract: Abstract: In China, camellia oleifera fruit is deeply loved by consumers as specific woody oil resource. Because of the composition of fatty acid for camellia seed oil is highly similar to olive oil, it is also known as "Oriental olive oil". However, the shelling operation of camellia oleifera fruit largely relies on natural drying, which is of low efficiency, high labor intensity, high processing cost, and great dependence on weather. In order to improve the performance of shelling machine for camellia oleifera fruit, increase the shelling rate and reduce the seed breaking rate, choosing the shelling rate and seed breaking rate as the indices, 3 aspects were studied based on the existing shelling equipment and practical engineering experience in this paper. Firstly, the physical parameters of camellia oleifera fruit were studied. The parameters such as density, bulk density, grain size, water content and proportion of each component of camellia oleifera fruit from Changning City were measured, which provided the data for the design of shelling machine parts. Secondly, the mechanism and main structure of the shelling machine were studied. In the beginning, the merits and defects of commonly-used methods for shelling were summed based on their working principle and mechanism. According to practical engineering experience and the measured data above, the final squeeze-rub shelling method for camellia oleifera fruit was determined. Then the structure of main parts was designed, which included the shelling device consisting of the roller, annular plate and the regulating mechanism, and the separation device consisting of stirring shaft and circular groove structure screen. Finally, the three-dimensional (3D) prototype model was established and the drawing design was completed. Thirdly, the operating parameters of shelling machine for camellia oleifera fruit were studied. The shelling machine for camellia oleifera fruit was manufactured based on the structure design, and then the operating parameters' optimization test was made. In the experiment, camellia oleifera fruit's particle size, shelling gap, speed of shelling motor, speed of separation motor were taken as single factors, respectively, and the shelling rate and seed breaking rate were taken as indices. The influence trend of these factors on the indices was drew out. Based on the result, the orthogonal experiment was designed, which aimed at studying the effects of the speed of shelling motor, the speed of separation motor and the gap of shelling on shelling rate and seed breaking rate. The results indicated that the water contents of the fresh camellia oleifera fruit, shell and seed were 60.08%, 74.55% and 45.60%, respectively. The particle size distribution was 20-50 mm, and the bulk density was 0.52 kg/L. The optimal combination parameters were that the speed of shelling motor was 125 r/min, the speed of separation motor was 343 r/min and the shelling gap was 12 mm. And under the condition, the shelling rate was 96.91%, the seed breaking rate was 3.38% and the production capacity was up to 2 t/h. The optimal parameters achieved in this paper can provide reference and technical support for the actual application of shelling machine for camellia oleifera fruit. And it will benefit the processing industry of camellia oleifera fruit.