The invention discloses an electric up latch device of a landing gear. The electric up latch device comprises a first motor and a second motor which are mutually a cold backup for each other, whereinthe first motor is connected with a gear arranged on a reducer through a first ratchet mechanism, and the second motor is connected with a gear arranged on a reducer through a second ratchet mechanism; a ball screw is fixedly mounted between an output shaft of the reducer and an up latch housing; a cam is integrally and pivotally arranged on the ball screw, and a spring is arranged on the ball screw between the cam and the up latch housing in a sleeving manner; and the cam is arranged under a locking arm and can push the locking arm, so that a first lock hook and a second lock hook are released by the locking arm to realize unlocking, or the locking arm is reset under the effect of a torsional spring, and the locking of the first lock hook and the second lock hook is realized. According tothe electric up latch device disclosed by the invention, a landing gear extending/retracting system is simplified, a conventional actuating cylinder, hydraulic system components and parts, atmospheric pressure system components and parts and the like are removed, so that the storing space is greatly saved, the weight is reduced, the reliability of the system is improved, and the maintenance costcaused by leakage failure is avoided.