► The quality of Zn–In–Sn–O (ZITO) films were adjusted by different gas (oxygen and argon) induced plasma ions bombarding (PIB) treatment. ► The contributions of PIB treatment on the structure, optoelectronic properties of ZITO film have been clearly defined. ► Briefly, PIB treatment can easily adjust the film quality in short time. ► Additionally, the film toughness not only was improved but also enhanced the structural stability by PIB treatment that was good for TCO film application in the flexible substrate. The quality of co-sputtering derived Zn–In–Sn–O (ZITO) film was adjusted by different gas (oxygen and argon) induced plasma ions bombarding (PIB) treatment. The result showed that the film conductivity could be improved after plasma bombardment. The increment of oxygen vacancies and plasma bombard-induced thermal energy were main reasons. Notably, the efficiency of Ar plasma bombarded for improved conductivity not only was better but also had a smoother surface morphology. Due to Ar ions will not react with metal atoms to form oxide and possessed a higher momentum. In addition, the O-rich layer on the ultra-surface not only was removed but also enhanced film reliability by plasma bombarded that could enhance the performance of optoelectronic devices.