The invention provides a film stretching loading unit with a position locking function, the film stretching loading unit comprises a substrate, a motor, a turbine worm assembly, a loading turntable, afastening clip, and a turntable positioning member; the motor is fixedly disposed on the substrate, the turbine worm assembly is rotatably fixedly disposed on the substrate, a worm is connected to anoutput shaft of an electrode, and transfers rotation outputted by the motor to a turbine, one side of the turbine is provided with a fan-shaped groove, and the vertical section of the loading turntable is same in shape as the vertical section of the fan-shaped groove, so that one end of the loading turntable can be inserted into the fan-shaped groove, the turbine can drive the loading turntable to rotate synchronously, the fastening clip fixes a film sample to be tested onto the loading turntable, so that the loading turntable can drive the film sample to rotate synchronously to pull the filmsample to turn upward and outward ; the substrate is provided with a positioning groove, and the positioning member can be inserted into the positioning groove to limit the axial rotation of the loading turntable.