The utility model provides a fixing structure of a sofa mattress layer. A sofa
bed comprises a left armrest, a right armrest and a
bed frame fixed between the left armrest and the right armrest, and an elastic layer and a
cushion layer are sequentially arranged on the
bed frame; a plurality of first connecting pieces are arranged on the elastic layer at intervals in the circumferential direction, and a plurality of second connecting pieces are arranged on the lower surface of the
cushion layer at intervals in the circumferential direction; and the first connecting piece and the second connecting piece pass through the middle connecting piece. The utility model further provides a sofa bed. The sofa bed comprises a
structural framework, a
cushion layer and an elastic layer, the cushion layer and the elastic layer adopt the fixing structure; the
structural framework comprises a left armrest, a right armrest, a bed frame and a bed board; the bed frame comprises a first bed frame and a second bed frame which are sequentially arranged in the width direction of the armrests; the first bed frame is fixedly connected between the left armrest and the right armrest; the second bed frame is rotationally connected between the left armrest and the right armrest; and the bed plates are respectively connected in the first bed frame and the second bed frame.