For the growing demand of actuation performance, a highly powerful IL-cellulose based biocompatible ionic actuator was developed by the plasticization treatment method. In view of the effects of plasticizing treatment, the electromechanical properties and electrochemical properties of biocompatible ionic actuator were mainly studied in this paper. The characteristic peaks scanned by FT-IR and the phase analysis tested by XRD showed that no regenerated substances in the IL-cellulosed membrane were generated under different plasticizing parameters. With the increase of the plasticizing bath concentration and plasticizing time, the porosity of the IL-cellulose layer obviously decreased with a good flexibility, which improved the inner ions movement channels. CV results revealed that the specific capacitance under plasticization parameter of 30%—120 min was a significantly higher than that other IL-cellulose membranes. The results of EIS and GCD demonstrated that the ions diffusion rate increased under different plasticizer concentrations, and the charge and discharge speed was faster than the initial state. However, the ion diffusion rate remained unchanged under different plasticizing time, and the power density was declining along with a deteriorated permeability of IL-cellulose membrane. Additionally, through plasticization treatment, actuators under plasticization parameter of 30%—120 min exhibited largest single cycle peak displacement and peak to peak displacement, which were 219 and 393% over un-plasticized actuators.