The invention relates to the field of technologies for machining connecting rods, and discloses a connecting rod fixture and a horizontal plane milling machine. The horizontal plane milling machine comprises the connecting rod fixture. The connecting rod fixture comprises a first fixture and a second fixture. The first fixture and the second fixture are respectively mounted on the horizontal plane milling machine, the first fixture is used for fixing a connecting rod body and comprises a first base and a first pressure plate, and the first pressure plate is mounted on the horizontal plane milling machine and presses the connecting rod body along the direction perpendicular to the axial direction of the connecting rod body; the second fixture is used for fixing a connecting rod cover and comprises a second base and a second pressure plate, and the second pressure plate is mounted on the horizontal plane milling machine and presses the connecting rod cover along the axial direction of the connecting rod cover. The connecting rod fixture and the horizontal plane milling machine have the advantages that the connecting rod body is fixed onto the first base, the first pressure plate moves onto the connecting rod body and is clamped by a first bolt, the connecting rod cover is fixed onto the second base, the second pressure plate presses the connecting rod cover, and a milling cutter can be started, so that the connecting rod body and the connecting rod cover can be machined, and the connecting rod fixture and the horizontal plane milling machine are high in work efficiency.