The invention discloses a clothes treating device and a box assembly thereof. The box assembly includes a first side plate and a second side plate which are oppositely arranged, an upper connecting reinforcing plate and a control panel, wherein the upper connecting reinforcing plate is disposed between the first side plate and the second side plate, and the two ends of the upper connecting reinforcing plate are connected with the upper end of the first side plate and the upper end of the second side plate respectively; the control panel is disposed on the first side plate and the second side plate and the front side of the upper connecting reinforcing plate, wherein the rear surface of the control panel is provided with a control panel clamping portion, the upper connecting reinforcing plate is provided with an upper connecting plate clamping portion, and the control panel clamping portion is clamped and connected with the upper connecting plate clamping portion. According to the box assembly for the clothes treating device, the clamped connection of the control panel and the upper connecting reinforcing plate is achieved through cooperation of the control panel clamping portion and the upper connecting plate clamping portion, connecting pieces such as bolts are omitted, the structure is simplified, the production cost is reduced, and the assembly efficiency of the box assemblyis also improved.