The study of the groove etched process for the hydrodynamic mechanical seals was reviewed,and the advantages and disadvantages of various machining techniques in the process of groove were also reviewed,including photochemical machining(PCM),electrical discharge machining(EDM),electrochemical machining(ECM),ultrasonic machining(USM),laser beam machining(LBM),and so on.It was pointed out that the techniques of PCM,EDM and LBM are feasible and successful,among them,laser beam processing(LBM) is the most widely used,but its processing mechanism has not been indepth studied.ECM technology and USM technology also has the feasibility of processing groove.Due to the advantages of a variety of processing technology,composite processing technology has greater advantages in the groove etched process,and is a future direction of development.The groove etched process technology will be in the direction of precision,complexity and efficiency along with the continuous development of precision machining technology.