The invention relates to a scale disk for nursing operation of low-molecular weight heparin injection. The scale disk comprises a main disk body and meter moving double wings. The main disk body comprises a positioning disk, an inner circumferential rail, an outer circumferential rail, a scale sector plate, a pointer positioning rod, and a concentric positioning rod. The inner circumferential rail is arranged on the outer edge of the positioning disk. The scale sector plate is slidably configured between the inner circumferential rail and the outer circumferential rail. The meter moving double wings are slidably configured on the outer circumferential rail of the main disk body. Aimed at injection medicine characteristics of low-molecular weight heparin, horizontal, longitudinal, and circumferential distances of an injection position are accurately controlled around 20 mm. through the positioning disk, an injection range is positioned, a central positioning plate aligns at a basic injection point, an injection forbidden annular plate shields an injection forbidden region, the pointer positioning rod positions angles and longitudinal interval, and the concentric positioning rod positions distance and horizontal interval. After positioning holes of the two positioning rods are overlapped, a position most suitable for injection is accurately founded, so operation of a nurse is more accurate and rapid, and difficulty of self-operation of an intern doctor and a patient is effectively reduced.