A buried power module for high/low voltage insulation is provided. The power module includes a first substrate, a second substrate and an insulating substrate. The first substrate includes a first control circuit and a light source, wherein the first control circuit controls the light source to emit light. The second substrate includes a light-sensing part, a second control circuit and a power device. The light-sensing part receives the light of the light source of the first substrate to send sensing information. The second control circuit correspondingly drives the power device in accordance with the sensing information. The insulating substrate is disposed between the first substrate and second substrate.