The invention discloses an artificial dam anti-seepage and reinforcing device and an anti-seepage and reinforcing method. The artificial dam anti-seepage and reinforcing device comprises a supporting frame, a first baffle, a second baffle and a driving mechanism, wherein the supporting frame comprises a base and a supporting shaft extending out of the side surface of the base; the first baffle is connected with the supporting shaft in a sleeving mode, the first baffle abuts against the side surface of the base, and the first baffle and the side surface of the base are fixed; the second baffle is connected with the supporting shaft in a sleeving mode and in movable connection with the supporting shaft, and grouting holes are formed in the upper part and the lower part of the second baffle correspondingly; and the driving mechanism is connected with the second baffle and used for driving the second baffle to keep close to or away from the first baffle. By means of the artificial dam anti-seepage and reinforcing device and the anti-seepage and reinforcing method, the problems that an existing artificialdam is severe in seepage, low in anti-seepage effect, low in structural strength and high in construction cost and repairing cost are solved.