With the development of high-power and high integrated radio frequency (RF) electronics, the thermal issue of high heat flux chip cooling is becoming urgent. Liquid cooling is preferable for RF electronic heat dissipation. Aluminum cold plate with single layer series flow channel is widely used for current RF electronics. However, the increased convective temperature rise and pressure drop restricts its application in future high heat flux RF electronic cooling. In this work, aimed at improving high-power RF linear chip array cooling ability, we propose a two-layer aluminum cold plate composed of liquid dividing layer and heat dissipation layer, forming a fully-parallel microchannel structure. The flow and heat transfer performances of the single-layer and two-layer cold plate are comparatively evaluated using a finite-element numerical simulation. Then, the effects of key parameters of the two-layer cold plate are analyzed, and the guidelines for choosing the parameters are presented. The results indicate that the proposed two-layer cold plate can simultaneously reduce the convective temperature rise, pressure drop and chip temperature deviation by 48%, 65%, and 67%, respectively.