Anti-solvent assisted crystallization (ASAC) approach was used to synthesize crystalline CH3NH3PbBr3 thin films with uniform microstructures through accelerated crystallization process at room temperature. The influence of different solvents and various interval dropping time on the final morphology was investigated. Photovoltaic devices with TiO2/CH3NH3PbBr3/spiro-MeOTAD structure were fabricated using ASAC approach without any post-annealing process. The devices were found to exhibit fast photocurrent response and small J-V hysteresis due to the room temperature processing that minimizes the formation of surface electron traps and corresponding slow transient current. The ASAC-CH3NH3PbBr3 solar cells exhibited open circuit voltage of 1.42V with champion power conversion efficiency (PCE) of 8.29%, much higher than the devices fabricated without using anti-solvent approach having a Voc of 1.01V and PCE of 3.15%. Our results demonstrate that ASAC approach can provide high performance room temperature fabrication method for low-cost perovskite solar cells.