The invention discloses a pair of dual-purpose smart bras, which comprises cups, shoulder straps, a bottom band, side panels and back straps, wherein a back buckle is arranged on the back straps; each cup comprises an upper cup and a lower cup; openings are formed between the upper and lower cups; zippers are arranged at the openings; the back buckle comprises a left side back buckle and a right side back buckle; a flat thin electromagnet group is arranged in the left side back buckle; a flat thin magnet is arranged in the right side back buckle; a controller is arranged on one back strap; a power supply, a fingerprint identification system and a conversion switch are arranged in the controller; the positive pole of the power supply is connected with the fingerprint identification system; the fingerprint identification system is connected with the conversion switch; the conversion switch is connected with the flat thin electromagnet group; the flat thin electromagnet group is connected to the negative pole of the power supply; a Bluetooth module is arranged on the conversion switch, and communicates with a mobile terminal. According to the dual-purpose smart bras, a detachable cup structure is adopted, so that the bras can be used as strap bras with 3/4 cups, and can also be worn as strapless decorative bras with 1/2 cups; in addition, a smart back buckle structure is additionally arranged, so that the dual-purpose smart bras are convenient and rapid.