The utility model relates to a mat coat structure on old way reconstruction porous asphalt road surface, include: old pavement, lay in waterproof bonding layer on the old pavement, lay in drainage top facing on the waterproof bonding layer, wherein, old pavement says at emergency vehicle that the outside plane degree of depth of milling of ab intra is graduallyd change to the the second set degree of depth by the first settlement degree of depth, the first settlement degree of depth is greater than the the second set degree of depth. The utility model discloses, mill the plane degree of depth what emergency vehicle said that the outside adoption of ab intra reduces gradually, can make the elevation in the outside that emergency vehicle said be less than or equal to the inboard to avoid forming the area that blocks water. When rainwater infiltration to drainage top facing bottom, can say along emergency vehicle and transversely trickle to the trackside edge, then discharge the rainwater through old pavement drainage facility, showing and improving drainage efficiency.