With the development of science and technology, more and more non-linear loads begin to be used, and harmonic pollution produced by non-linear loads is more and more serious. The main harm of harmonic includes loss increase, insulation damage, and the influence on normal operation of electric equipment and so on, as a result, harmonic pollution governance is of real significance. This paper analyzed the source and harm of harmonic in electric power grid and proposed the different methods for harmonic governance and overall governance method for electric power grid harmonic based on the basic idea for harmonic governance and all kinds of harmonic sources.