The invention relates to an automobile seat, which belongs to the technical field of automobiles. The automobile seat solves the problems of complexity, heaviness, inconvenient disassembly and assembly and high price of the entire conventional automobile seat. The automobile seat comprises a seat plate and a backrest connected with the seat plate, wherein the backrest is provided with a guide hole parallel to the seat plate; an extension unit capable of translating along the guide hole is arranged in the guide hole; and a limiting structure capable of limiting the travel of the extension unitis arranged between the extension unit and the guide hole. The automobile seat has the advantages of convenient use, small space occupation, sitting comfort and the like.