Hi @Lili1002, let me see if I can help out here.
I have translated your question to English as this is an International forum, please post any replies in English and it will be easier for me and other users to assist you.
Xperia XZ1 do have an IP-rating of IP65/68, which means it has undergone certified tests to measure its resistance levels to both dust and water. However, it has not been tested for exposure to liquids such as salt water, chlorinated water, hot water, sweet, sour or salty drinks or other liquid chemicals, so I would not advise exposing your phone to salt water.
I hope that answered your question. If you want to read more about water and resistance in Xperia, click here.
