The utility model relates to a deep-sea ballast release device which comprises a support; the support is provided with an electric solenoid component which comprises a deep-sea electric solenoid and an electric solenoid plunger, and a two-stage lever release component which comprises a first stage of lever and a second stage of lever; the first and the second stages of levers can respectively rotate on vertical surfaces around supporting points thereof on the support; the position of the center of gravity of the first stage of lever is bound by one end of the electric solenoid plunger; the force point of the first stage of lever is the center of gravity of the second stage of lever; and the force point of the second stage of lever is a ballast hanging point. The first and the second stages of levers are mutually matched so as to obtain longer resistance arm with smaller space and control ballast release with smaller power after the electric solenoid is electrified, so that the use is safe and reliable. The deep-sea ballast release device has simple and compact structure, can be reused, can be used in full sea depth, resists pressure and corrosion, can reliably carry and release 100kg ballast, has short response time, and is particularly applicable to the ballast release of underwater robots and deep sea engineering machinery.