A lot of ping-pong balls may fall on ground round the ping-pong table, whenever people take part in the ping-pong sport,. In order to collect them conveniently, this paper puts forward a new method that applies aerodynamic principles. By vacuum, ping-pong balls are collected into the collecting box. The special vacuum ball-collector is designed and made. The results show that ball-collector is better than current other ping-pong ball-collectors at time and work. It has broad application worth.