The invention discloses a test device and method for the vertical initial motional impedance of a bucket foundation. The test device comprises the bucket foundation, a fan tower, a mass block, an extension thrust rod, a low-frequency electromagnetic exciter, an exciter fixing rack, a force sensor, a flange connecting disc, a soil pressure sensor, pore water pressure sensors, acceleration sensors, strain pieces, an energy-dissipation material, water drain pipes, a test iron box, steel angle ribs, steel plate reinforcing ribs, a loading frame, a power amplifier, a swept signal generator, a dynamic acquisition instrument and a computer. The test device is composed of a load loading part and a bucket foundation part, so that the vertical motional rigidity and the vertical motional impedance are measured. The low-frequency exciter is utilized for loading, and the motional rigidity of the bucket foundation is obtained by measuring the action force and displacement of a soil body. The motional impedance of the bucket foundation is obtained by applying vertical initial displacement to the mass block and measuring an attenuation curve. By adoption of the test device and method for the vertical initial motional impedance of the bucket foundation, the vertical initial motional impedance and influence factors of the bucket foundation can be accurately studied, and a basis is provided for further studying.