Aave has just released an upgrade to the clearing engine in V4, which meets my needs. If you have experience in Aave liquidation, you will probably know that the original liquidation system had a fixed close factor. Simply put, even if you only need to liquidate a small part to bring back the health factor>1, the liquidator can still liquidate according to a fixed proportion, which will result in the liquidated person being forced to lose a lot of collateral, which is an excessive liquidation. In V4, the liquidator does not always repay the debt at a fixed percentage, but only allows the liquidation to "just" bring the borrower's health factor back to a certain target value. (This target value is set by governance) In practical operation, how much debt does the protocol accountant need to repay to increase this position from the current health factor to the target value? The liquidator can only liquidate up to this limit at most. Reduced excessive liquidation and is friendly to the liquidated parties. In addition, the liquidation reward has also changed from static to dynamic, and the V3 reward does not automatically change with the level of position risk. There is a problem with this, which is that it is not conducive to clearing the most dangerous positions first. In V4, the liquidation reward is dynamic and linked to the health factor. The lower the health factor, the more dangerous the position, and the higher the liquidation reward, which motivates liquidators to prioritize the most dangerous positions.