An improved modular SVG parallel interleaving modulation method is proposed to solve the problem of large current Total Harmonic Distortion (THD) when interleaving parallel modulation of modular SVG system. Firstly, the current ripple of the interleaving parallel system is analyzed according to the structure of the interleaving parallel circuit, and the calculation formula of the maximum current ripple output of the interleaving parallel system is derived. Secondly, the improved interleaving parallel modulation method is compared with the traditional interleaving parallel method, and the improved method is superior to the traditional method in many aspects such as suppressing ripple, etc. Finally, the method proposed is verified by Matlab/Simulink simulation experiments to check the feasibility and effectiveness of the improved modular SVG parallel interleaving modulation. The results show that this interleaving parallel mode is very effective at lower switching frequencies, and it can be used in the field of low frequency and low current interleaving parallel systems. This work is supported by National Natural Science Foundation of China (No.51777060).