A gas-driven asteroid sampling device was designed. Based on the transient mesh sliding method of computational fluid dynamics (CFD), coupled simulations were conducted using Fluent software and EDEM. Universal experimental validation was performed under a gravitational model environment, and the effects of the shape of the isobaric groove outlet on particles under microgravity, as well as the effects of different inlet angles and inlet pressures on the number of collected particles, were analyzed. Ultimately, a gas-driven sampling device for small particles on the asteroid surface was designed, capable of sampling movable solid small particles covered on the bottom surface of the device in a microgravity environment. Physical models for microgravity particles and fluid flow were established. The authenticity of these physical models was verified through the CFD-DEM coupled simulation model and ground experiments. It was confirmed that the isobaric groove structure is beneficial to the flow field within the device, and the device’s inlet section was optimized using flow field pressure, velocity, particle velocity, and collection quantity as indicators. The overall setup of the device provides a basis for the design of gas-driven samplers.