The invention relates to a magnetic core. The magnetic core is characterized by comprising an upper magnetic core, a lower magnetic core, an intermediate-column magnetic core and side-column magnetic cores, wherein the upper magnetic core and the lower magnetic core are arranged vertically, the intermediate-column magnetic core is arranged at the middle, the side-column magnetic cores are arranged at the two sides of the intermediate-column magnetic core, the upper magnetic core and the lower magnetic core have first magnetic conductivity, the side-column magnetic cores have second magnetic conductivity, and the intermediate-column magnetic core has third magnetic conductivity. The other technical scheme of the invention provides a magnetic coupling inductor of an interleaving parallel converter. The invention provides a coupling induction magnetic core combination scheme in which magnetic cores having different magnetic materials, different magnetic conductivities and different sizes are matched to one another, thus, the magnetic coupling integrated inductor is wide in magnetic core mode selection range, the coupling degree K is flexible and convenient to adjust, the magnetic core structure of the inductor can be optimized, and mass production cost is reduced.