1. There is something wrong with the check valve: turn the cover clockwise. If the cover moves, it means that the cover has no air pressure. The main reason why the lid can't be opened is that the check valve doesn't return, which makes the lid unable to be opened. The solution is to find a hard object (such as chopsticks), press the check valve, push the check valve back and open the lid.

2. There is air pressure in the pot: If the pot cover is rotated clockwise, it may be that there is air pressure in the pot and it must be cooled and released. The methods of pressure relief generally include natural cooling, air cooling and boosting. If you are not in a hurry to boil, you'd better use natural cooling to release the pressure. Generally speaking, there is no need to increase the pressure to release it unless absolutely necessary. If this method is not used, pay attention to the gas ejected from the air outlet at the top of the pressure cutting.