Why does my iPhone 7 often receive spam messages? Is there any way to solve it?

Brother, this is pushed by ICLOUD Cloud.

Close iMessage, as follows: 1. Click Settings on the home screen, 2. Find the "Information" column and click "Enter", 3. Click the switch to the right of iMessage to turn it off. IMessage is an instant messaging software launched by Apple, which can send short messages, videos and so on. It has high security. IMessage is different from SMS/MMS service of operators. Users only need the data support of WiFi or 3G network to complete communication.

Another way is to set iCloud to close the calendar and enjoy it.