大事化小小事化了

大事化小小事化了:

Literally means:

reduce the trouble to the minimum; minimize the responsibility of those to blame

Actually means:

化 means “change…into"; 了 means “finish or over". The phrase literally means turning a big trouble or issue into a small one, and a small trouble or issue into nothing at all. Figuratively it means solving problems or settle disputes by means of reducing the conflict until it disappears. It is often used to advise people to eliminate their conflicts and to be reconciled with each other.

The phrase also figuratively means intentionally understating the severity or harm of an accident that needs to be seriously dealt with, of which the cause must be found out and for which the responsibility needs to be investigated and affixed, so that the responsibility of those to blame can be abated or they can be exempted from penalty. It often shows the speaker's dissatisfaction, criticism or reproach toward such an act. Derogatory.

化，把…变成。了，结束，完了。本义是把大事变成小事，把小事变成没事。比喻采用缩小直至消除矛盾的方式来处理纠纷，平息争端。常用来劝说别人消除矛盾，重新和好。

比喻对需要查明原因、追究责任、严肃处理的事件，故意缩小事件的严重性质或危害程度，从而减轻或免去有关人员的责任。多表示说话人对这种行为的不满、批评或责备。