In order to solve the problem of damage in the process of picking, collecting and transporting fresh grapes, a bag-in-bag packaging device was designed to work with the robotic arm during the picking operation to avoid damage through bag-in-bag packaging, and the grapes can fall directly into the collection basket after the packaging was completed to improve the efficiency of mechanical harvesting of fresh grapes. Firstly, based on the damage indexes such as grape surface hardness, quality loss rate, surface rupture index and puncture rupture force, the optimal inflation air pressure of the bag-in-bag packaging device was determined to be 4kPa, and the suction cup diameter, bag-in-bag distance and ipsilateral suction cup distance were determined to be 30mm, 125mm and 95mm through the bag-in-bag force analysis and bag opening shape analysis during the bag propping process;then the relationship between grape fruit image size and inflation time was established. The relationship between grape fruit image size and inflation time was modeled, and the inflation time was automatically adjusted to ensure that grapes of different sizes could achieve the optimal protection effect after inflation and packing. Finally, the test results showed that the success rate of nondestructive collection was 95%, the average packing time was 28.4s, the maximum atmospheric pressure deviation was 0.2kPa, the average air pressure deviation rate was 1.1%, the average damage rupture rate was 1.5%, the average threshing rate was 0.2%, and packaging efficiency was 126 strings/h. The bag-in-bag packaging device had stable operational performance, high success rate of non-destructive packaging of fresh grapes, which can avoid damage, ensure freshness, and improve picking and collecting efficiency.