1. The steps to upgrade the iphone system on the device are as follows;
1. Open the Settings icon on an iphone connected with WiFi.
2. Click the General option in the settings list, and then click Software Update.
3. The system will connect to the network to detect updates, and if there are updates, you will be prompted to download and install them. Just follow its tips.
Second, use iTunes to update the system on the computer. The steps are as follows.
1. Connect the iphone to the computer, open the iTunes software, and click the "iphone" button in the upper right corner.
2. When iTunes detects the connected device, it will automatically connect to the Internet to detect whether there is an available update system, and then it will automatically pop up the upgrade update.
3. If it doesn't pop up, you can also click the "Check for Update" button in the iphone summary interface.
4. After detecting the available update of the current iphone, download the update and upgrade according to the prompt.