Urban railways are an important part of China’s rail transit “four network integration”. Their stations are typically situated in suburban regions, characterized by long lines and large station spacing. Traditional manual inspections entail a substantial workload and exhibit low efficiency; multi-rotor UAVs are constrained by limited endurance and airspeed, leading to low efficiency in daily long - range inspections. Fixed-wing UAVs have the advantages of long endurance and high altitude, and are more cost-effective for daily routine inspections when deployed in long areas. They complement the functions of multi-rotor UAVs in rail transit inspection applications. The flight control system of a fixed-wing UAV is a multi-channel, strongly coupled complex system. Based on its lateral and longitudinal dynamic models and navigation technology, this paper designs different types of PID control strategies for the control channels, such as roll angle, pitch angle, altitude, vertical velocity, and flight airspeed, and verifies the feasibility of the control algorithm through numerical simulation. Finally, through on-site test flights, the stability and reliability of the single aircraft flight control system were verified, providing technical support for the availability of fixed-wing unmanned aerial vehicles in the inspection of long sections of urban railways.