Blanching green beans will make them easier to cook in the subsequent stir-frying process, and it can avoid stir-frying with other dishes when the other dishes are too rotten or too old. Green beans should not be cooked for a long time, otherwise they will become discolored. Blanching green beans need to prepare a clean pot, pour a small half pot of water into the pot and boil over high heat, wait for the water to boil and then put the green beans into the pot for blanching. After two minutes of blanching, the green beans out of the cool water for a moment to control the water and spare. Dry green beans also need to be soaked for at least 3 hours beforehand.