A distributed synchronous measuring system（DSMS） based on the global positioning system（GPS） synchronous clock-carrier power source is proposed. It consists of three parts， the GPS synchronous clock-power source module， the field information synchronous measuring unit（SMU） and the transmission line that links the two. The DSMS has the following key feature that the GPS synchronous clock-carrier power source is an independent module loaded with GPS clock signals， which can provide the operating source and high accuracy synchronous clock signals to all the SMUs in a monitoring terminal substation（power plant， power station， etc）， simplifying the SMU structure. Both the fixed time interval sampling mode and the self-adapting sampling mode in the field SMU are designed as options， and the synchronized time-mark can be set at will.