Abstract: With the development of the power electronic converter, the requirements for Electromagnetic Interference (EMI) filter size become stricter. The prospect of application of active EMI filter (AEF) is promising due to its small size and high integration. However, compared with traditional EMI passive filter, the problem of poor high-frequency EMI suppression in AEF still hasn't been solved so AEF has been not widely used in industry. In order to analyze the common problems existing in AEF, taking the Feedback Current-Sense Current-Compensation AEF as an example, the Boost converter was used as an experimental platform to show the design process of parameters in AEF. The mechanism by which the gain bandwidth product of the operational amplifier limits the high frequency EMI suppression effect of AEF was analyzed, and the method of combining Chaotic Pulse Width Modulation (CPWM) with AEF design was proposed to enhance the EMI high frequency suppression effect. The simulation and experimental results show that the desired amplified gain of AEF can be reduced by CPWM, thus the EMI high-frequency inhibitory effect will be enhanced. No extra costs are needed for this optimization method, which is suitable for high power density power electronics devices, and the high-frequency EMI suppression of AEF is effectively improved.