CH3NH3PbI3 perovskite is an organic-inorganic hybrid material that has attracted attention recently as a candidate for photovoltaic applications because of its superb semiconductor characteristics. The first principle is adopted to study the structural, density of states and optical properties of orthorhombic self-doped perovskites (CH3NH3)1−xPbI3(A:=0.00, 0.25, 0.50, 0.75, 1.00). With the content of vacancy at the A sites increasing, the results indicate that: (i). the cell volume decreases weakly firstly, and then increases linearly; (ii). the band gap decreases monotonically from 1.656 eV to 1.584 eV; (iii). these self-doped can be used and controlled by vacancy at the A sites in photon absorbers in thin-film as solar cells perovskites based on the high absorption feature of these materials in visible energy range.