The invention discloses a foot pad device for outdoor dining tables and chairs. The foot pad device includes a hoop used for being connected with the outdoor dining tables and chairs; a connection rodis vertically and fixedly arranged on the hoop, the connection rod is fixedly provided with a storage barrel, the bottom of the storage barrel is provided with a through hole communicated with the outside, the bottom surface of the storage barrel is fixedly provided with an annular electromagnet, the bottom surface of the annular electromagnet is fixedly provided with a plastic film used for blocking the through hole, magnetic mud is stored in the storage barrel, and the storage barrel is internally provided with a pressurization device acting on the magnetic mud; the portion, located betweenthe hoop and the storage barrel, of the connection rod is fixedly provided with a planar disk used for placing the dining tables and chairs, the pressurization device includes a pressurization platearranged in the storage barrel in a sliding mode, the upper surface of the pressurization plate is rotatably connected with a work rod, the top of the storage barrel is fixedly provided with a cover body, and the work rod penetrates through the cover body in a threaded mode and is communicated with the outside. According to the foot pad device, softness of the magnetic mud is made use of, the magnetic mud can be well used for filling gaps between various objects on the ground, the environment in which the tables and the chairs are placed is improved, and the stability of placement of the tables and the chairs in any environment is ensured.