The utility model discloses a hydraulic circuit conversion adapter, which comprises an installation part and a main body part, wherein the installation part comprises a first flange and a second flange respectively arranged at two ends of the main body part, an oil inlet and one oil outlet or two oil outlets are respectively arranged on two end faces of the main body part, or a plurality of oil inlets and a plurality of oil outlets are respectively arranged on the two end faces of the main body part, the oil inlet is communicated with the one oil outlet or the two oil outlets through oil ways, and the oil outlet/outlets is/are communicated with the only oil inlet. A coiling machine is further disclosed. The coiling machine comprises a coiling mechanism, an expanding and contracting cylinder, a rotating joint and the hydraulic circuit conversion adapter, wherein the coiling mechanism of a coiling block is connected with the expanding and contracting cylinder through the hydraulic circuit conversion adapter, and the hydraulic circuit conversion adapter is the above hydraulic circuit conversion adapter. The hydraulic circuit conversion adapter enables the rotating joint to be generalized, and the coiling machine can avoid replacing of the rotating joint caused by replacing of the expanding and contracting cylinder, so that maintenance cost is saved.