The invention relates to a high-density PCB high-efficiently suppressing edge radiation and a method for suppressing edge radiation. The EMI of the PCB mainly derives from a power distribution network. A power/ground plane in the power distribution network forms a resonant cavity which may cause serious electromagnetic radiation at resonant frequency. The high-density PCB and the method for suppressing edge radiation may high-efficiently shield the electromagnetic radiation in the power/ground and reduce the EMI to an ideal state. A laminate is an embedded planar capacitor laminate. The embedded planar capacitor formed by a thin dielectric and power ground plane pair can be viewed as AC short circuit at a high frequency band and may achieve a very good electromagnetic radiation suppression effect.