A battery pack, comprising a box and a battery module, the battery module being fixed in the box, wherein the battery module comprises: a battery cell arrangement structure comprising a plurality of battery cells stacked on each other; and an end plate, the end plate being located at an end part of the battery cell arrangement structure in a length direction, and the end plate comprising a first mating part and a second mating part; wherein the second mating part is located below the first mating part in a height direction of the battery module, and a thickness of the first mating part is t1, a thickness of the second mating part is t2, t1 >t2, a direction of the thickness is parallel with the length direction; wherein a mounting beam is disposed in a cavity of the box, and in the length direction of the battery module, the mounting beam is located at the end part of the battery cell arrangement structure; in the length direction, the second mating part has a fifth bottom wall mated with the mounting beam, a preset gap t is provided between the fifth bottom wall and the mounting beam in the length direction; a step part is formed between the first mating part and the second mating part, and in the height direction, the mounting beam abuts against the step part; the first mating part is provided with a second mounting groove and a third mounting groove, and in the height direction of the battery module, the second mounting groove is located above the third mounting groove; the battery pack comprises a first cable tie and a second cable tie, and the first cable tie and the second cable tie both surround an outer side of the battery cell arrangement structure; a portion of the first cable tie is located at the second mounting groove, and a portion of the second cable tie is located at the third mounting groove; and a tensile strength of the first cable tie is greater than a tensile strength of the second cable tie, and an elastic modulus of the first cable tie is greater than an elastic modulus of the second cable tie; the first cable tie and the second cable tie are arranged in the height direction of the battery module, and the second cable tie is close to one end of the battery module that is fixedly connected to the box; wherein in the length direction, a depth of the second mounting groove is T4, a depth of the third mounting groove is T5; and a thickness of the first cable tie is T1, and a thickness of the second cable tie is T2, where 0<T4-T1<0.5 mm, and 0<T5-T2<0.5 mm. a battery cell arrangement structure comprising a plurality of battery cells stacked on each other; and an end plate, the end plate being located at an end part of the battery cell arrangement structure in a length direction, and the end plate comprising a first mating part and a second mating part; wherein the second mating part is located below the first mating part in a height direction of the battery module, and a thickness of the first mating part is t1, a thickness of the second mating part is t2, t1 >t2, a direction of the thickness is parallel with the length direction; wherein a mounting beam is disposed in a cavity of the box, and in the length direction of the battery module, the mounting beam is located at the end part of the battery cell arrangement structure; in the length direction, the second mating part has a fifth bottom wall mated with the mounting beam, a preset gap t is provided between the fifth bottom wall and the mounting beam in the length direction; a step part is formed between the first mating part and the second mating part, and in the height direction, the mounting beam abuts against the step part; the first mating part is provided with a second mounting groove and a third mounting groove, and in the height direction of the battery module, the second mounting groove is located above the third mounting groove; the battery pack comprises a first cable tie and a second cable tie, and the first cable tie and the second cable tie both surround an outer side of the battery cell arrangement structure; a portion of the first cable tie is located at the second mounting groove, and a portion of the second cable tie is located at the third mounting groove; and a tensile strength of the first cable tie is greater than a tensile strength of the second cable tie, and an elastic modulus of the first cable tie is greater than an elastic modulus of the second cable tie; the first cable tie and the second cable tie are arranged in the height direction of the battery module, and the second cable tie is close to one end of the battery module that is fixedly connected to the box; wherein in the length direction, a depth of the second mounting groove is T4, a depth of the third mounting groove is T5; and a thickness of the first cable tie is T1, and a thickness of the second cable tie is T2, where 0<T4-T1<0.5 mm, and 0<T5-T2<0.5 mm.