The present invention provides an OLED pixel structure, comprising red, green, blue sub pixel areas, and the red, the green, the blue sub pixel areas respectively comprise a substrate, an anode formed on the substrate, a flat layer formed on the anode, an organic light emitting layer formed on the flat layer and a cathode formed on the organic light emitting layer, and an aperture area is formed on the flat layer, and the organic light emitting layer contacts the anode through the aperture area, and the anode comprises a positive electrode and a positive electrode compensation area coupled to the positive electrode, and the cathode, the positive electrode compensation area and a sandwiched layer between the cathode and the positive electrode compensation area constitute a compensation capacitor, and the compensation capacitor respectively makes total capacitance values of the red, green, blue sub pixel areas are equivalent to reach the capacitance value required by an drive circuit of the OLED element.