The invention provides a passive stability-enhanced deformable undercarriage air-ground flying robot which comprises a body, deformable undercarriage devices, wing fuselage protection frames, rotor devices, an electromagnetic shielding cabin and an automatic pilot, wherein a general mechanical extension interface with one rotational degree of freedom is installed at the upper part of the body, the interface is provided with a CAN bus connection port, and end work modules can be connected according to different tasks; the deformable undercarriage devices are installed on the body, and diversion trenches are arranged on the deformable undercarriage devices so as to provide passive stability-enhanced airflow for the robot provided by the invention; the wing fuselage protection frames are installed at the tails of the deformable undercarriage devices; the rotor devices are installed on the body; the electromagnetic shielding cabin is installed at the lower part of the body; the automatic pilot is installed in the electromagnetic shielding cabin; and the automatic pilot respectively drives the deformable undercarriage devices to realize switching between a flying mode and a ground mode of the robot provided by the invention. According to the invention, propeller protectors, undercarriages and passive stability enhancers are integrated in the deformable undercarriage devices, so that the self-weight is reduced, and the viability of power components and effective loads in complex environments is improved.