Peng, J. An, Y.W. Fu, S. Huang, L. Huang, M.Y. Li, M.T. Li, Y. Li, Z.P. Liu, Y.D. Lu, X.H. Luo, X.B. Wang, S. Xu, S.Y. Yuan, Y. JACoW Publishing Geneva, Switzerland 2226-0366 978-3-95450-194-6 10.18429/JACoW-LINAC2018-TUPO114 English 573-575 TUPO114 lattice DTL linac MMI quadrupole Contribution to a conference proceedings 2019 2019-01 https://doi.org/10.18429/JACoW-LINAC2018-TUPO114 http://jacow.org/linac2018/papers/tupo114.pdf The China Spallation Neutron Source(CSNS) accelera-tor systems is designed to deliver a 1.6GeV, 100kW pro-ton beam to a solid metal target for neutron scattering research. It consists of a 50keV H⁻ Ion Source, a 3MeV Radio Frequency Quadrupole (RFQ), an 80MeV Drift Tube Linac (DTL), and a 1.6GeV Rapid-cycling Synchro-tron (RCS). The DTL consists of four tanks. In 2017, three of four tanks have been commissioned successfully, and beam has been accelerated to 61MeV with nearly 100% transmission. However, in July 2017, one quadrupole contained in the drift tube was found fault, the beam transmission decreased to 80%. A new lattice has been designed and the 100% transmission has recovered. In January 2018, the last tank of the DTL has been commissioned and accelerated the H⁻ beam to the design energy of 80MeV for the first time. The commissioning progress and the measurement results before and after lattice adjustment will be presented.