The present invention discloses a charging device for a portable electronic product with a charging circuit, including: a mechanical energy collecting device configured on a main body of the portable electronic product, adapted to collect and store part of mechanical energy of a user of the portable electronic product; a mechanical energy-electrical energy converting device coupled with the mechanical energy collecting device, adapted to convert mechanical energy stored by the mechanical energy collecting device into electrical energy; and a processing circuit connected between an output end of the mechanical energy-electrical energy converting device and an input end of the charging circuit of the portable electronic product, adapted to process energy output from the mechanical energy-electrical energy converting device and input processed energy to the charging circuit of the portable electronic product.