The invention discloses a window for a low-rise fabricated building, and a mounting process thereof. The window comprises a window body, a first mounting member and a second mounting member; the firstmounting member and the second mounting member are used for mounting the window body; a square hole is formed in the side wall of the window body, and the window body is connected with a connecting member through the square hole; the connecting member comprises a square mounting base; a first connecting block is fixedly connected to the lateral corner angle of the mounting base; the other end ofthe first connecting block is fixedly connected with a square block matched in the square hole; the connecting member is connected to the window body by inserting the square block into the square hole; the window body is provided with a window groove for mounting the window body; a first connecting groove and an accommodating groove are formed in positions, corresponding to the first connecting block and the mounting base, on the edge of the window groove. The window for the low-rise fabricated building has the advantages of simple structure, convenience in transport, simplicity in assembly for mounting, shortened construction period, high airtightness and high stability.