The invention discloses a device for ground resonance test of a coaxial dual-rotor helicopter, and relates to the field of aircraft test devices. The device comprises upper rotor propeller blades (1), an upper rotor propeller boss (2), an upper rotor boss shaft (3), an upper rotor driving gear (4), an electric motor (5), a box body (6), a spring (7), a damper (8), a supporting plate (9), a cardan joint (10), a chassis (11), brackets (12), bearings (15), pins (16), a counter weight (17), a lower rotor boss shaft (18), a lower rotor driving gear (19), an electric motor bevel gear (20), a lower rotor propeller boss (22) and lower rotor propeller blades (23). The device disclosed by the invention can simulate the resonance effect of the coaxial dual-rotor helicopter, and a test device for researching the resonance of the coaxial dual-rotor helicopter is provided.