The wireless charging coil of OnePlus 9pro mobile phone is located in the middle of the back of the mobile phone. The wireless charging coil is placed inside the fuselage and close to the back cover of the mobile phone, so it cannot be seen from the outside of the fuselage. When using the wireless charging function of the mobile phone, the mobile phone needs to be placed on the wireless charger. In order to ensure the balance of the phone and facilitate the user to place the phone, the wireless charging coil of all mobile phones is located in the middle of the back of the phone.