The multiple interfaces are necessary for exciton separation in bulk heterojunction (BHJ) solar cells and the continuous pathways for carrier transportation in the donor:acceptor blend films,especially along vertical direction, for efficient charge collection.Therefore film morphology is critically important to satisfy both in constructing high performance organic solar cells (OSCs).In this work, cooperative effect of solvent additives and solvent flux treatment to the film morphology was confirmed.Furthermore, the correlation between single processing parameter and resulting morphology has been investigated.Our results show that the film morphology can be tuned by changing the volume fraction of solvent additive.Beyond that,after methanol fluxing, the OSC performance was improved significantly, as short circuit current density (Jsc) increases from 13.85 mA/cm2 to 15.17 mA/cm2 and fill factor (FF) from 62.9% to 65.7%,simultaneously.As a result, power conversion efficiency (PCE) increases from 6.79% to 7.67%.The favorable morphology was further investigated using the time-of-flight secondary-ion mass spectroscopy (TOF-SIMS), the atomic force microscopy (AFM).