1. If you can't access the Internet, try to turn it off, turn it on and restart it, and check whether the traffic capping threshold of this month is reached, whether the mobile data set by the mobile phone is turned on, and whether the mobile data option APN and the mobile phone name are set to 3gnet. 2. If you still can't access the Internet, you can troubleshoot the problem in the following ways: confirm whether there is an available network in the place with strong signal; Check whether the account still has telephone charges, and if the balance is insufficient, it needs to be recharged before it can be used; Confirm whether the parameters of the mobile phone have been set; Check whether the USIM card is inserted. If it's plugged in and still doesn't work, go to the business hall to check whether the USIM card is faulty or not. Check whether there is any problem with the mobile phone, and change the machine for testing; If the traffic is capped, it will also lead to the inability to access the Internet. After shutdown, restart the search network.