A foldable support, comprising: a bottom plate; a first support plate and a second support plate, wherein the first support plate is connected to the bottom plate, the first support plate is capable of rotating relative to the bottom plate, the second support plate is connected to the first support plate, the second support plate is capable of rotating relative to the first support plate, and the second support plate is configured to match an external structural member to support the first support plate; and a first magnetic member and a second magnetic member, wherein the first magnetic member is arranged on the first support plate, the second magnetic member is arranged on the second support plate, and the first magnetic member is configured to attract the second magnetic member in a case that an included angle between the first support plate and the bottom plate is less than a preset angle, to enable the second support plate to be fitted with the first support plate; and the first magnetic member is further configured to repel the second magnetic member in a case that the included angle between the first support plate and the bottom plate is greater than or equal to the preset angle, to enable the second support plate and the first support plate to be arranged at an included angle; and a rotary mechanism, the first support plate is rotatably connected to the bottom plate through the rotary mechanism, characterized in that the rotary mechanism has a first conductive contact point; and the first conductive contact point is configured to conduct with the first magnetic member in a case that the included angle between the first support plate and the bottom plate is less than the preset angle, to enable magnetism of the first magnetic member to attract that of the second magnetic member; and the rotary mechanism has a second conductive contact point; and the second conductive contact point is configured to conduct with the first magnetic member in a case that the included angle between the first support plate and the bottom plate is the preset angle, to enable magnetism of the first magnetic member to repel that of the second magnetic member. a bottom plate; a first support plate and a second support plate, wherein the first support plate is connected to the bottom plate, the first support plate is capable of rotating relative to the bottom plate, the second support plate is connected to the first support plate, the second support plate is capable of rotating relative to the first support plate, and the second support plate is configured to match an external structural member to support the first support plate; and a first magnetic member and a second magnetic member, wherein the first magnetic member is arranged on the first support plate, the second magnetic member is arranged on the second support plate, and the first magnetic member is configured to attract the second magnetic member in a case that an included angle between the first support plate and the bottom plate is less than a preset angle, to enable the second support plate to be fitted with the first support plate; and the first magnetic member is further configured to repel the second magnetic member in a case that the included angle between the first support plate and the bottom plate is greater than or equal to the preset angle, to enable the second support plate and the first support plate to be arranged at an included angle; and a rotary mechanism, the first support plate is rotatably connected to the bottom plate through the rotary mechanism, characterized in that the rotary mechanism has a first conductive contact point; and the first conductive contact point is configured to conduct with the first magnetic member in a case that the included angle between the first support plate and the bottom plate is less than the preset angle, to enable magnetism of the first magnetic member to attract that of the second magnetic member; and the rotary mechanism has a second conductive contact point; and the second conductive contact point is configured to conduct with the first magnetic member in a case that the included angle between the first support plate and the bottom plate is the preset angle, to enable magnetism of the first magnetic member to repel that of the second magnetic member.