A button cell, comprising: a cell core of button cell and a housing assembly of button cell , the housing assembly of button cell comprises: a housing and a conductive part, the housing and the conductive part enclosing together to form a holding cavity for holding the cell core of button cell ; wherein, the housing is provided with a through hole , and the conductive part penetrates through the through hole , and an insulating rubber ring for sealing and insulating the conductive part and an inner wall of the through hole is provided between the conductive part and the inner wall of the through hole ; and the conductive part comprises a columnar part (22a2) penetrated through the through hole , and an end of the columnar part (22a2) facing the cell core of button cell is provided with a sheet part (22a1) integrally formed with the columnar part (22a2), and an end of the columnar part (22a2) facing away from the cell core of button cell extends outwardly with a flanging (22a3) around the columnar part (22a2); and the axial direction of the columnar part (22a2) is provided with a fabrication hole (22a4), wherein the sheet part (22a1) of the conductive part and a second tab of the cell of button cell are welded together on a side of the sheet part (22a1) located in the fabrication hole (22a4); wherein the housing has two oppositely disposed end surfaces, and a sidewall is located between the two end surfaces; and the conductive part is located on one of the end surfaces; wherein hardness of the conductive part is smaller than hardness of the housing ; wherein at least a part of a housing wall of the housing has a thinning area , and thickness of the housing wall in the thinning area is smaller than thickness of other parts of the housing wall. the housing is provided with a through hole , and the conductive part penetrates through the through hole , and an insulating rubber ring for sealing and insulating the conductive part and an inner wall of the through hole is provided between the conductive part and the inner wall of the through hole ; and the conductive part comprises a columnar part (22a2) penetrated through the through hole , and an end of the columnar part (22a2) facing the cell core of button cell is provided with a sheet part (22a1) integrally formed with the columnar part (22a2), and an end of the columnar part (22a2) facing away from the cell core of button cell extends outwardly with a flanging (22a3) around the columnar part (22a2); and the axial direction of the columnar part (22a2) is provided with a fabrication hole (22a4), wherein the sheet part (22a1) of the conductive part and a second tab of the cell of button cell are welded together on a side of the sheet part (22a1) located in the fabrication hole (22a4); wherein the housing has two oppositely disposed end surfaces, and a sidewall is located between the two end surfaces; and the conductive part is located on one of the end surfaces; wherein hardness of the conductive part is smaller than hardness of the housing ; wherein at least a part of a housing wall of the housing has a thinning area , and thickness of the housing wall in the thinning area is smaller than thickness of other parts of the housing wall. <EOS>