Abstract: Based on the precipitation data of automatic observations and NCEP (1°×1°) 6h ranalysis data, the study on the persistent heavy rainfall event caused by the Typhoon Candu was made through the analyses on energy, south wind pulsation, temperature advection and terrain effect in the west of Sichuan Basin.The results show that the combination of Mongolia high and west of Pacific subtropical high, divergent stream filed in upper level and the active southwest monsoon benefit steady moisture into the South China Sea transporting to the rainfall area;the heavy rain occurred in the unstable atmospheric stratification environment;Pulsation formated by the landed typhoon cause wind speed and direction convergence significantly, lower warm advection trigger the development of MCS, topographic uplifting to strengthen the convergence of warm air rising and the rainfall was increased.