Abstract: Grape variety is plentiful, and can be divided into wine grape and table grapes in general. Xinjiang, Bordeaux and California are called the "grape plant heaven". However, the wine grape is still hand-harvested, moreover labor cost for harvesting is more than 50% of the total cost during production period. Fruit-pedicle separation is a key link in the mechanized harvesting. Grape reciprocate swinging according to a certain frequency and amplitude is inspired by oscillating mechanism, then the resulted inertia force can eliminate the fruit-pedicle connection force to realize fruit-pedicle separation. Normal inertial force plays the major role in grape and pedicle separation. For this experiment, vibration separating test device base on crank and rocker mechanism was designed and built. Eccentric disc was driven by motor, making grapes clamping on the rocker swing. The fruit- pedicel vibration separation model was built. Movement path and velocity were obtained by analyzing the movement of the crank rocker mechanism. Fruit-pedicle separation amplitude equation was gained by analyzing the fruit-pedicle separation conditions. At the same time, the main influence factors of separation, motor speed, eccentric distance and vibration rocker length were determined through the analysis of the models. The experimental study on grape was carried out. Using Chardonnay and Cabernet Sauvignon planted in Xinjiang Shihezi city, 152 groups of grapes were selected as samples. The sampling dates were respectively on September 9 and 14, 2014. The sample selection was based on grape average value of mass and length. The wine grape samples after taken were refrigerated rapidly to retain freshness. Notation was used to calculate the rate of grape separation with the formula. Experiment factors levels was achieved on the basis of preliminary experiment, and L9 (34) orthogonal test plan was designed. Each test group was replicated three times, and the average value of three replicates was used as the test group result. Grape peduncle was fixed on the dynamic and settled fixture of the vibration separate test device. And vibration time was 10 s. Visual and variance analysis methods were used to analyze the data. Observation from the experiment indicated that eccentric distance, rocker length and motor speed affected the separating effect of Chardonnay and Cabernet Sauvignon in primary and secondary. Analysis of variance showed that eccentric distance and rocker arm length influenced separation rate was significant, and motor speed affected significantly for Chardonnay, but not for Cabernet Sauvignon. The observation from the experiment and variance analysis of data were consistent. Cabernet sauvignon exceeding Chardonnay in mechanical separation rate was achieved by analyzing the influencing factors that controlled the separation rate. Therefore, Cabernet sauvignon was more suitable for mechanical harvest. The separation rate of optimal parameters that the motor speed was 245 r/min, eccentric distance was 75 mm, and vibration rocker length was 200 mm. These parameters were verified. The result showed the separation rate of wine grape was 95.2%. The range of grape vibration frequency was 2.11 to 3.69 Hz and grape peduncle amplitude was 169.8 mm. All of those were achieved by putting the optimal parameters in motion analysis and fruit-pedicle separation condition. The study could provide a reference to the design and optimization of wine grape harvester.