A 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 a 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.