The invention discloses a portable ground online flight simulation system, which includes a console computer, a simulation computer, a hub and an airborne device. The console computer is connected to the simulation computer through an Ethernet, and the hub is respectively connected to the simulation computer and the simulation computer through cables. Airborne equipment connection, the console computer is a high-performance PC, used for simulation process control, simulation data display, simulation data display record, UAV initial parameter setting, wind field environment injection and fault model injection, The simulation computer is an embedded computer, which is used for real-time solving of the unmanned aerial vehicle mathematical model, real-time simulation of sensors, wind field model solving, fault model solving, physical electrical interface simulation, and the hub is used for the simulation computer Distribution of electrical connections with onboard equipment. The invention checks the UAV system in an efficient, safe, economical and comprehensive manner, ensures the flight safety of the UAV, comprehensively verifies the correctness and rationality of the UAV system, and provides pilots with UAV system information without building The iron bird test bench is low in cost, good in economy, short in cycle, small in size and easy to move.