Abstract: With the increasing density of the railway network and the increasing frequency of extreme weather such as downbursts, the risk of high-speed trains being attacked by downbursts is increasing, thusly it is particularly important to evaluate the safety of high-speed trains under the action of downbursts. A series of rigid model pressure tests were conducted on a high-speed train subjected to a downburst using a physical simulator. The investigation was carried out on the impact of line type and jet tilt on the aerodynamic characteristics of the high-speed train under the downburst. Selected were the safety indicators such as derailment coefficient, wheel load reduction rate, wheelset lateral force, and wheel-rail vertical force to evaluate the running safety of the train. The findings indicate a sharp decrease in the wind pressure coefficient as the radial distance increases, transitioning from wind pressure to wind suction on all sides except for the right side of the train (windward side), where there is an initial increase followed by a decrease and maintenance of pressure, exhibiting a wind pressure distribution similar to that of the crosswind at a relative radial distance around r/D_jet=1.0. The extreme values of lateral force coefficient C_Fx, lift coefficient C_Fz and rolling moment coefficient C_Mx are larger when the train is located on an embankment and viaduct compared to the ground, but the type of line has no influence on the radial position where the extreme of aerodynamic load coefficient occurs. With the increase of jet tilt, the peak values of lateral force coefficient C_Fx and rolling moment coefficient C_Mx decrease gradually, and the radial position of the peak value is further away from the centre of the downburst. The safe operating speed domain is the greatest when the train is located on the embankment, followed by ground and, the least on the viaduct, i.e., the train is the most dangerous when running on the viaduct. The existence of jet tilt can increase the allowable running speed of a train under the same downburst wind speed, and the safe operating speed when the train is located at the back side of the downburst is greater than that at the front side.