The invention discloses an LEO/MEO double-layer satellite network low-overhead flooding method and a satellite node. A source node floods to a same layer and a different layer, and the satellite nodereceiving a link state information packet from an interlayer link is called a proxy satellite node; the source node and the satellite node are used as original points of the layer, the satellite nodejudges the position relation with the original point after receiving the link state information packet, the link state information packet is transmitted along the link between same-rail satellites inthe case of same layer and same rail and is also transmitted along the link between satellites on different rails; the link state information packet is only transmitted along the link between satellites on different rails in the case of same layer and different rails; and if the satellite node is the proxy satellite node, the link state information packet is transmitted along the link between same-rail satellites and is also transmitted along the link between satellites on different rails; and the repeatedly received link state information packet is discarded during the transmission. By adoption of the LEO/MEO double-layer satellite network low-overhead flooding method, the flooding overhead when the terrestrial Internet OSPF protocol is applied to an LEO/MEO double-layer satellite networkis reduced, and meanwhile the effect of the traditional flooding of link state information transmission in the whole network is achieved.