The utility model provides an oil pumping unit system efficiency on-line test system based on SCADA. The system comprises a data acquisition system, an SCADA system, a relational database and a systemefficiency analysis and optimization system, the data acquisition system is used for acquiring and storing an indicator diagram and a power diagram; wherein the SCADA system is used for acquiring anindicator diagram and a power diagram stored in the data acquisition system through an oil field communication network and synchronously storing the indicator diagram and the power diagram; wherein the relational database is used for receiving and storing the indicator diagram, the power diagram, the crude oil density and the working fluid level data, and the system efficiency analysis and optimization system is used for reading the indicator diagram, the power diagram, the crude oil density and the working fluid level data in the relational database and analyzing to obtain the efficiency of the oil pumping unit system. On the basis of real-time data provided by an SCADA system, online testing of system efficiency is achieved, results are applied to energy consumption analysis, and optimization of production parameters of a rod-pumped well is guided.