The advantages of sodium percarbonate as a carrier of “solid hydrogen peroxide” compared to hydrogen peroxide in the liquid phase are considered. Methods of homogeneous (activation by ultraviolet radiation, electrodischarge plasma, in ultrasonic field, by metal ions) and heterogeneous (by natural and artificially synthesized minerals, iron nanoparticles that are immobilized on support materials, nanoparticles of iron compounds, bimetallic nanocomposite, ferrocene) activation of sodium percarbonate and their application in advanced oxidation processes of organic compounds based on it are presented. It was found that the acidic environment is more effective for homogeneous activation of sodium percarbonate by metal ions (in particular Fe2+), and a neutral or alkaline environment is more suitable for heterogeneous activation of sodium percarbonate.