Data consumption has nothing to do with WIFI. Mobile phones sometimes generate traffic consumption without any reason, because some mobile phone software will automatically connect to the Internet in the background for updates or data synchronization. Whether you turn on GPRS or not, there may be a traffic consumption.
There are two ways to solve this problem, one is to set, turn off the background data, turn off the automatic synchronization, turn off the automatic update of all software; At the same time, the connection permission of the application is also set, only allowing the Internet through WIFI; Usually keep GPRS in the off state, you can avoid traffic loss.
Another simple way to go to the business hall to turn off the mobile phone GPRS Internet access function.