The present invention discloses a circuit board, including a substrate and a magnetic core, where the magnetic core is embedded into the substrate, at least one turn of a winding conductor wound around the magnetic core is arranged on the substrate, each turn of the winding conductor includes a first end-surface conductor and a second end-surface conductor that are separately arranged on two ends of the magnetic core, and each turn of the winding conductor further includes a first side-surface conductor that penetrates through the magnetic core from an inner side of the magnetic core and a second side-surface conductor that penetrates through the magnetic core from an outer side of the magnetic core. The circuit board and the power conversion apparatus having the circuit board provided by the present invention, achieve larger inductance, save materials, and reduce cost for fabricating a power conversion apparatus.