The invention discloses an electro-pyrolytic urea solution ammonia production device used for selective catalytic denitration and an application thereof. The device comprises a urea dissolution system, a urea solution storage system, a urea pyrolysis system and an automatic control system, wherein the automatic control system controls the urea dissolution system to prepare a certain concentration of urea solution, the obtained urea solution is stored in the urea solution storage system, the automatic control system analyzes the NOx concentration to calculate the amount of the urea solution, the solution of the urea solution storage system is added in the urea pyrolysis system, an electro-pyrolytic urea solution device in the system pyrolyzes the urea solution through electric heating and generates NH3, and NH3 is mixed with the flue gas to enter a selective catalytic reduction (SCR) denitration device and perform a denitration reaction. The electro-pyrolytic urea solution ammonia production device adopts electric energy to pyrolyze and control and has the characteristics of short response time, high efficiency and the like; and the device uses electric energy as the heat source and has the characteristics of low secondary pollution, economy, high efficiency and simple control.