The cell culture apparatus can be used for the research on cell biology, space biotechnology and space medicine. In this article, a flow-loading automatic cell culture device is designed and manufactured, which can be used for automatic vitro cell culture in underground and space microgravity environment. It can provide periodic and quantitative input of different reagents to the cell culture plate regularly, and meet the requirements of miniaturization, convenient assembly and high reliability required by space cell culture. The whole device adopts the modular design method, and uses Solid Works software to establish 3D models of basic components, reagent supply components and culture components, respectively. The Flow Simulation module in Solid Works software is used to conduct finite element analysis, fluid simulation, and structural optimization of the pin plate, the key component connected between the cell culture device and the cell culture plate. The velocity field and pressure field of the channel inside the pin plate are observed, and the channel is optimized by replacing right angles with rounded corners. The results show that the device is feasible and can meet the requirements of cell culture device. The fluid stability in the optimized pin-plate channel is stronger, and the flow rate and pressure distribution are more uniform. In the ground environment, the optimized needle plate has increased the speed uniformity of fluid in the transverse channel by 95% , 96% , and 94% , respectively under low, medium, and high flow rates. Similarly, in the longitudinal channel, the speed uniformity has been increased by 68% , 70% , and 72% , respectively under low, medium, and high flow rates. The experimental results show that the optimized flow at the outlet of the pin-plate channel is closer to the set output flow at the inlet pump. The designed device can be used in space biotechnology research.