Planar on-chip micro-supercapacitor (POMS), as a new energy storage device, can be easily used for integration with micro/nano electronic devices to provide an effective power source. In this work, a modified liquid-air interface self-assembly method is introduced to fabricate reduced graphene oxide (RGO) films on the silicon wafer for POMSs. The RGO films have good surface morphologies, uniform thickness (313.073nm) and high conductivity (640.3Scm(-1)) after hydroiodic acid treatment. The POMS exhibits a maximum stack capacitance of 351.59mFcm(-3) and 98.17% capacitance of POMSs was retained after charging and discharging for 2000 cycles at a scan rate of 1000Vs(-1). Specially, there is still a high power density (587.85mWcm(-3)) at an ultra-high scan rate of 5000Vs(-1) as well as an ultra-fast charging-discharging time (14ms). The demonstrated POMS has a good application foreground in the preparation of high-performance integrated micro-devices. [GRAPHICS] .