Shunt active power filter（SAPF）will cause harmonic amplification at the load side when it is used at capacitive nonlinear load. Firstly

the system structure of SAPF application is introduced

then

SAPF harmonic compensation mathematical model based on voltage non-linear load is set up

the mechanism causing the harmonic amplification at the non-linear load side is analyzed and corresponding formula is derived and

at the same time

as for the issue of harmonic amplification effect at the load side

such three measures on changing impedance ratio

reducing compensation factor and shunting compensation capacitance are proposed.Finally

the simulation study is performed by the simulation software and the measures adopted in the projects are given. The effectiveness of the proposed measures is verified by the simulation result and project example.