The invention discloses a recycle method and a recycle apparatus of dilute formic acid from industrial waste water and solves problems that a conventional dilute formic acid concentrating technology is high in cost and the industrial waste water pollutes environment due to direct discharging. The recycle method is characterized in that the industrial waste water containing large amount of the dilute formic acid is concentrated for recycling a concentrated formic acid product through a phosphorus acid circulation with the waste water recycle apparatus which is composed of a storage kettle (7), a water absorption column (8), a filling material (9), a spray nozzle (10), a condenser (12), a storage tank (16), a heating medium outlet valve (17), a heating medium inlet valve (18), a dehydration kettle (19), a circulating pump (20) and the like. The recycle method is advanced and reasonable, is convenient to operate and is free of pollution. The method and the apparatus can be widely applied in dehydrating recycle of waste water containing a large amount of the dilute formic acid in a chemical industry production enterprise and can achieve abundant economic benefit for the enterprise.