Abstract: The influencing factors and the reason of IR-drop and electromigration were analysed. Taking the design of power/ground distribution network for transmitter of digital terrestrial television multimedia broadcast for an example, power/ground distribution network which ensured the normal operation in maximum IR-drop area was built around standard cells. Maximum IR-drop estimation was made by treating standard cell area as power/ground and resistor network. Finally, macro area was converted to standard cell area to build another power/ground network considering the difference between core ring and macro ring. The networks in standard cells area and in macro area formed a integrated network. The method was used in the floorplan phase of the actual design, which shows its efficiency and reliability of power distribution. The successes of IC tape-out and function accuracy prove the practicality and efficiency of the method.