Birds strike and flight without approval of UAV are two major hidden dangers threatening the safety of flight takeoff and landing, and the above-mentioned birds and UAV are both low and slow small flying objects. In order to protect the safety of the airport clearance area, it is necessary to develop an early warning system with the function of anti-low and slow small flying objects. A real-time detection system for low and slow small flying objects were designed and implemented. Based on the field programmable gate array (FPGA) driven camera arrays, the sky videos with large field of view were collected in real time. Combining the parity shunt algorithm and inter-frame differential algorithm which were suitable for hardware operation to detect moving targets, the system frame rate reached 17 fps@1 024×768 pixel, and the average detection accuracy was 99.69%. Gigabit ethernet, optical fiber and switch were used to transmit the front-end runway video to the back-end tower command center, which supporting 3 km long-distance transmission. Compared with the traditional software-based serial processing, the proposed system has the advantages of high real-time, low power consumption and small size, which is suitable for deployment in practical application scenarios.