Based on a mount of practice this paper summarizes effective methods of improving SCADA analog data’s time-synchronization

as follows: ①GPS is used by all automechanism in scada system

and alarming mechanism againts clock synchronization failure is taken; ②Dead-zone is not made in analog module equipment for analog data being acquired more faster in substations; ③101 and 104 protocol are implemented by master stations and substations

period of cyclic data transmission is less than 0.2 seconds; ④All analog data acquisition in substations is started up and gathered by master stations with Group Interrogation message

or General interrogation is taken manually by master station to gather all data from substations; ⑤General interrogation data is filled into realtime database

then the database is backed up to EMS study database and important analog data is inserted into history database.