There are still many ways to retrieve deleted contacts, because no matter which brand of mobile phone, it will have its own cloud. If you logged in to a certain brand when you performed a one-click backup of your mobile phone address book, If the mobile phone account is synchronized and backed up to the cloud, then after the mobile phone address book is accidentally lost, you can use the same brand of mobile phone to log in to the same account, and you can directly synchronize the contact address book stored in the cloud to the new device. This way you can retrieve deleted contacts. Address book contacts are very important information, and it is troublesome to lose them. If you have not backed up your mobile phone address book to the cloud with one click before, you may not be able to retrieve it, so you must have the habit of backing up and back up to the Internet in advance. On the Internet or in your account, you can try QQ Synchronization Assistant. It will back up your mobile phone address book to the Internet with one click and intelligently manage your address book. It can not only synchronize it back to your phone at any time, but also retrieve accidentally deleted contacts! It is also very simple to use this tool to back up mobile phone contacts with one click. First, install the "QQ Synchronization Assistant" on both the old and new mobile phones. Then, on the old phone, enter the synchronization assistant, tap the big synchronization button, and log in to QQ. After logging in, synchronize the contact information to the cloud. Finally, open the synchronization assistant on the new phone, click the synchronization button, log in to the same QQ account, and synchronize the contact information from the cloud back to the phone address book. I chose this tool because of its simple steps to operate. According to my understanding, this tool is just like QQ emoticon roaming. Even if you log in to QQ elsewhere, the emoticons can be shared and used. If there is no other better way, you can try this backup method first. The operation is also very simple, much simpler than other methods.