The Cs3Sb photocathode is an old topic in photo gun field. With our current preparation system, Cs3Sb photocathodes were deposited in 2011. After two cycles Yo-yo process performed in the 10-9 mbar environment, the QE reached 1.5% @ 262 nm. SEM measurement was done to detect the film quality, which shows the Cs/Sb layer with the stoichiometric rate of 2.7 on the Mo sample. The substrate was completely covered with homogeneous film. On the film some islands with the size of µm level are observed, which response actually the rich distribution of cesium.