Real time character is the common request of a pipeline SCADA system, as the own BIOS clock of the Cross-platform devices are not same and the transit delay of the network, time accuracy cannot be guaranteed which influent the product data transit in time and valid. This paper introduces a method of using the GPS clock source, NTP protocols and CIP protocols to achieve the initiative synchronizing system for Cross-platform SCADA system, which can ensure time accuracy and consistency with all the network devices, servers, clients and programmable logic controllers. Practice proved this method is valid.