The difficulties and challenges of the UDC technology were analyzed， the progress of each key technical point were presented，and potential solutions were explored. The transmittance of UDC area could be improved to 20% by “Driving Circuit Edge-placed”， reducing the pixel anode size， etc.， and it could basically meet the needs of the front camera on the mobile phones. “One sub-pixel driving circuit drives the same color sub-pixels” could reduce the number of lines while keeping the number of OLED pixels unchanged. Destroying the pattern regularity of the UDC area could suppress the diffraction to improve the selfie performance of the front camera. Optimized pixel layout could reduce the obviousness of the separatrix between the low PPI and high PPI area. The brightness and color differences between the UDC area and the main screen could be eliminated by optimizing Gammas of two screen areas and Demura algorithms.