The piezoelectric characteristic of two-dimentional materials are of great interest as high-performance piezoelectric potential applications[1].In order to practical applications,CVD-based large-area monolayer MoS2 is essential.However,CVD-based MoS2 has the intrinsic defects such as sulfur vacancy during the growth process and this defect is one of the main reasons for the screened piezoelectric potentail[2],[3].So only small peizoelectric potential induced power output was observed from the pristine CVD-grown MoS2.Here we demonstrate high performance piezoelectric nanogenerator using CVD-based MoS2 by additional sulfur treatment process during MoS2 growth.The measured piezoelectric coeffecient(d11)of CVD grown large-area monolayer MoS2 is 3.73 pm V-1 using lateral PFM method,and it generates a peak power density of a 0.8 pW which is 10 times higher than that of as-synthesized MoS2.Also to explore the reasons why additoinal sulfur treated MoS2 shows enhanced piezoelectric characteristics,XPS,PL and KPFM anylysis was performed.