The utility model discloses and provides a liquid conveying device which is simple in structure, small in size, low in energy consumption and convenient to operate. The liquid conveying device comprises a cavity, at least one rotary driving element and at least one reciprocating element, wherein the rotary driving element and the reciprocating element are arranged in the cavity, rotation of the driving element can enable the reciprocating element to move axially to form a volume, so that liquid is sucked from the upstream side in the conveying direction or the liquid is conveyed to the downstream side to be discharged, and the end surface of the driving element and the end surface of the reciprocating element are respectively a curved surface with at least one convex part and at least one concave part. When the convex part of the driving element is located at the concave part of the reciprocating element, the driving element is attached to the reciprocating element. When the convex part of the driving element makes contact with the convex part of the reciprocating element, the reciprocating element moves axially to form the volume.