The present invention is an impeller automatic lifting mechanism for a waterwheel, comprising an impeller, at least one impeller capable of rotating water and flowing, characterized in that the floating raft is provided with at least one baffle at the downstream end of the impeller, and a a connecting rod assembly capable of driving the impeller, the end of the deflector sinking into the water and inclined along the water flow direction； when the impeller is running at a high speed, the end of the deflector can be impacted by a relatively high speed water flow, and the deflector is deflected upward And through the connecting rod assembly to drive the impeller up, while reducing the depth of the impeller to reduce the flow and increase the water； the impeller speed decreases to deflect the deflector, so that the depth of the impeller water increases and the flow is increased, and the water is reduced. In turn, the impeller will be used to stimulate the redistribution of energy dynamics during the splashing and creating, respectively, to improve work efficiency and save energy.本創作為一種水車的葉輪自動升降機構， 包括一浮筏、至少一能夠旋轉打水及造流的葉輪，其特徵在於：該浮筏設有至少一位於該葉輪下游端的導流板，以及一能帶動該葉輪舉升的連桿組件，該導流板末端沉入水中並順著水流方向傾斜；當該葉輪高速運轉時能以較高速的水流沖擊導流板末端，令導流板偏轉上浮並透過連桿組件帶動葉輪向上舉升，同時減少葉輪的入水深度而減少造流、增加水花；該葉輪轉速下降使導流板偏轉下沉，令葉輪入水深度相對增加而增加造流、減少水花，進而讓葉輪將分別用於激發水花和造流時所消耗的能量動態性的重新分配，以提高工作效率並節省能源。
