Effective　control　of　the　perovskite　crystallinity,　homogeneity　and　surface　morphology　is　very　important　for　state-of-the-art　perovskite　solar　cells　to　retard　the　charge　recombination　at　the　grain　boundaries.　In　this　work,　we　develop　a　facile　approach　to　promote　the　growth　of　high　quality　perovskite　films　that　features　a　conductive　glass-assisted　annealing　route.　Such　a　novel　annealing　route　not　only　confines　the　evaporation　of　the　residual　solvent　effectively　to　gain　high-crystallinity　and　micrometer-sized　grains　of　CH3NH3PbI3　films,　but　also　decreases　the　number　of　non-radiative　recombination　sites　and　facilitates　charge　transportation　in　the　microstructural　perovskite　films　dramatically　compared　with　those　obtained　through　the　conventional　annealing　route,　resulting　in　a　remarkably　improved　power　conversion　efficiency　along　with　an　inconspicuous　hysteresis.　The　best　performing　cell　exhibits　a　PCE　boosted　to　18.08%　compared　with　16.18%　achieved　in　the　control　one.　And　the　optimized　1　cm2　device　based　on　the　reported　method　shows　a　satisfactory　efficiency　of　15.77%.　©　2018　The　Royal　Society　of　Chemistry.