Most linear regression based harmonic source responsibility division methods are based on the instantaneous values of voltage and current. This is inconsistent with the situation that the power quality daily monitoring system mainly provides statistical values such as voltage and current RMS. In view of this, this paper proposes a method that can be used to estimate multi-harmonic division of responsibilities on the engineering and is based on the short-circuit capacity at the busbar and the measurable voltage and current parameters. In this method, the voltage value at the PCC and the feeder current data of each harmonic producer on the system side will be measured from power quality test equipment. These data will be Fourier decomposed into the fundamental and harmonic voltage in PCC incoming and outgoing. The projection of the voltage on the PCC when each harmonic source acts alone is used as the basis for the division of harmonic responsibility. This paper also applies this method to the research and development of power quality monitoring and analysis system and realizes PQDIF format conversion and harmonic source identification. This work is supported by the Science Research Project of Shandong Science and Technology Department: Research on High-order Robustness Dispatch Theory Accommodating High-proportion Renewable Energy Generation (No. ZR2018MEE041).