Abstract: A lost circulation detection device includes a first detection member and a second detection member, a first signal transmitter and a first signal receiver are disposed on the first detection member, and the first signal transmitter transmits a signal along an axial direction of a rockshaft so that the first signal receiver acquires data information of drilling fluid in the axial direction of the rockshaft; a fluid channel penetrating through the second detection member is disposed in the second detection member, and the fluid channel is configurable to be in communication with the rockshaft; a second signal transmitter and a second signal receiver are disposed oppositely on two sides of the fluid channel, and the second signal transmitter transmits a signal along a center line of a second accommodating groove, so that the second signal receiver acquires data information of drilling fluid in a circumferential direction of the rockshaft.