A housing device with slidable engagement includes a housing body, a fitting, and a sliding buckle. The housing body includes an opening side and a lateral adjacent to the opening side. The lateral has a through hole, and an inner surface of the lateral is provided with a guide structure. The fitting is inserted into the housing body through the through hole. The sliding buckle is slidably assembled on the guide structure. The sliding buckle includes two clamping arms, and the two clamping arms correspondingly clamp to an outside of the fitting.