The invention discloses an underground interchange. The underground interchange comprises an east-west main tunnel and a north-south main tunnel which intersect with each other, wherein the east-west main tunnel is positioned on a lower side of the north-south main tunnel; two ends of the east-west main tunnel are taken as an east road junction and a west road junction respectively; two ends of the north-south main tunnel are taken as a south road junction and a north road junction; an east-to-west right-turn ramp and a north-to-east left-turn ramp are connected between the east road junction and the north road junction; a west-north connection tunnel is connected between the north road junction and the west road junction; a west-to-south right-turn ramp and a south-to-west left-turn ramp tunnel are connected between the west road junction and the south road junction; an east-west connection tunnel is connected between the south road junction and the east road junction. The underground interchange has the advantages of simple structure, need of small underground space area, short building period, low cost, easiness in ensuring a line index, prevention of traffic flow intersection, high vehicle passing efficiency, low energy consumption, and high security performance; the problem of interchange of underground tunnels can be solved well.