The invention discloses a slow-release dronedarone hydrochloride capsule and preparation method and application thereof. A slow-release dronedarone hydrochloride pellet comprises a medicated pellet core, an isolating coating layer, a slow-release coating layer and a protective coating layer from inside to outside, wherein the medicated pellet core comprises the following specific components in percent by weight: 10-25% of dronedarone hydrochloride, 10-30% of an adhesive and 10-60% of a sucrose blank pellet core. The slow-release preparation can prolong the duration of the treatment concentration of the dronedarone hydrochloride in a body to 12 hours, reduce side effects caused by excessive fluctuation in blood drug concentration, and reduce the medicine taking times.