The present application discloses a magnetic core structure and an electric reactor. The magnetic core structure includes an upper cover plate and a lower cover plate which are arranged oppositely and at least one wrapping post having two ends connected to the upper cover plate and lower cover plate, respectively. A cross-sectional area of the upper cover plate and/or of the lower cover plate is larger than that of the wrapping post. The upper cover plate, the lower cover plate and the wrapping post are made of a magnetic powder core material, an amorphous material, a nanocrystalline material or a silicon steel material. Since the cross-sectional area of the upper cover plate and/or of the lower cover plate is larger than that of the wrapping post, this may bring excellent DC-Bias characteristic to an electric reactor or inductor, and make the electric reactor or inductor have lower magnetic core loss.