Combined sofa

The utility model relates to a combined sofa which is simple in structure, can be freely combined and connected and is diversified in styles. The combined sofa comprises at least two square seats, at least two backrests and at least two armrest seats, wherein all the sides of each square seat are respectively provided with more than two blocking grooves; first fixture blocks which are matched with the blocking grooves so as to enable the backrests to be arranged on the seat are respectively arranged on all the backrests; second fixture blocks which are matched with the blocking grooves so as to enable the armrest seats to be arranged on the seat are respectively arranged on all the armrest seats; the cross section areas of the blocking grooves, the first fixture blocks and the second fixture blocks are sequentially decreased from top to bottom.