This is a problem that the transparent mobile phone case can't solve, because the existence of water vapor is inevitable.
First, remove the phone case from the phone. Note: Many transparent mobile phone cases are fragile, so be careful when disassembling them. Wipe the removed mobile phone and mobile phone case with paper towels or rags respectively. After wiping, put the mobile phone case into the water basin for soaking, and at the same time, it can also wash away the dirt that is difficult to erase in the water. After washing, soak it for 5 seconds, so that the static electricity on the mobile phone case can be fully removed. Then put your fingers on both sides of the phone case and take them out of the basin. After the mobile phone case is taken out of the water, never wipe it with anything, not even your hands. Shake off the water from the phone case and put it on the table to dry. If you really can't wait, you can also use a hair dryer to blow dry the phone case with cold air. After drying, the watermark of the mobile phone case disappears.