Drones are classified as radio equipment and fall under China's restricted import/export items. According to customs regulations, if you carry a drone into China, you must first apply to the local radio management authority, and go through customs clearance procedures with the approval document, which requires declaration.
For other electronic devices, if they are within the reasonable quantity for personal use and do not exceed the duty-free allowance (e.g., for travelers entering the country for the first time within 15 days, purchases abroad within CNY 5,000 and duty-free shop purchases within CNY 3,000), no declaration is needed, and you can choose the Green Channel for customs clearance. If they exceed the relevant limits or are restricted items, you must declare them to the customs, fill in the Declaration Form for Baggage of Incoming and Outgoing Personnel of the People's Republic of China, and choose the Red Channel for clearance.