The development history and technical overview of HPPO process by direct oxidation of hydrogen peroxide are reviewed at home and abroad, including the technical features and process flow of Basf/Dow chemical, Evonik/Uhde company, Sinopec and Yida chemical. The mechanism of HPPO process,the conditions of side reaction, the choice of reaction solvent and the purification method of PO are analyzed in detail. Some key problems in HPPO production process are put forward.