This application discloses a battery module, a battery pack, and a device using a secondary battery. The battery module includes: a battery cell assembly, including at least two battery cells arranged along a third direction, where each of the battery cells includes electrode terminals; and a first busbar, including a main portion and two connecting portions, where an extension direction of the first busbar tilts against the third direction at a preset angle, the two connecting portions are connected to the electrode terminals of the two battery cells in an identical battery cell assembly respectively, the main portion is connected between the two connecting portions, a deformation inducing portion is disposed on the main portion, and the deformation inducing portion is configured to reduce at least a force required for deforming the main portion along a first direction.