Perovskite solar cells (PSCs) have attracted widespread attention owing to their high photovoltaic conversion efficiency and low manufacturing costs. The crystallinity of the PSC film significantly affects the PSC’s photoelectric conversion efficiency. In this study, the crystallinity of the perovskite film was investigated by changing the mixing ratio of two antisolvents [methyl acetate (MA) and chlorobenzene (CB)] to optimize the preparation of the perovskite film. The use of MA as an antisolvent resulted in the formation of perovskite crystals with an average size of 182 nm, with the largest size reaching 498 nm. However, the pores had a detrimental impact on the photovoltaic conversion efficiency. The addition of CB at varying proportions increased the average size of perovskite crystals to 348 nm. With 40 vol% CB, the largest crystals showed a size of 772 nm. Furthermore, the number of pores was significantly reduced, and surface roughness was diminished to 17.6 nm, resulting in a photovoltaic conversion efficiency of 1.54%. However, 50 vol% CB stratified the perovskite layer, which decreased the grain size, surface roughness, and photovoltaic conversion efficiency.