In this work, we develop a method to enhance photovoltaic performance of perovskite film by directly mixing an anti-solvent, chlorobenzene, into the perovskite precursor. Using precursor with 30% chlorobenze, the power conversion efficiency of the champion device is improved from 15.24 to 18.48% because of a thicker perovskite film with enlarged grain size. In addition, the chlorobenzene-used device shows much less degradation in normalized power conversion efficiency after 120 h strorage in ambient air without encapsulation. Because we obtain thicker perovskite film by adding anti-solvent in precursor solvent, less material is wasted, benefiting the commercialization of the perovskite devices.