The method of polarized combination method of many laser beams by phase - conjugate is studied. The seeder is a laser machine of Cr4 + ∶YAGQ - Switched twisted mode and , the divided/ combined component is a polarizing plate。Finally three laser beams were combined by phase - conjugate mirror (PCM) ,and the parameters of output laser were 10Hz ,150mJ ,4ns , M21. 6.