Arthrospira platensis has attracted attention due to its ability to produce valuable compounds such as polyphenols. However, the setting up of efficient methods for their profitable recovery are currently hot investigation topics, which has been recognized as a big challenge. This work was aimed to study the recovery of phenolic compounds from A. platensis biomass in hydroalcoholic solutions and the antiradical power (ARP) by high pressure/temperature extraction (HPTE) in stirred reactor. This study demonstrated that HPTE is an efficient green extraction process to obtain high-ARP phenolic-rich hydroalcoholic extracts from A. platensis biomass; therefore, may be used as a potential natural source of bioactive compounds to formulate new functional foods or prepare dietary supplements.