The cloud detonation devices typically form a fuel air mixture cloud with an approximate cylindrical shape. The morphological parameters of the cloud closely related to the charge structure strongly affect the spatiotemporal evolution law of its detonation overpressure field， which in turn has a significant impact on its detonation overpressure damage power. In order to explore the morphological effects of cloud， through the numerical calculation method for ideal detonation in cylindrical cloud， the complex dynamic process of waves during its detonation process was analyzed. The evolution and distribution law of the cloud detonation overpressure field was investigated. A similar decay law of the radial far-field peak overpressure with scaled distance was established．The dependence relationship between the detonation overpressure damage radius and the morphological parameters （ratio of radius to height） of the cloud was provided. The research results indicated that there was a significant bimodal phenomenon in the radial far-field overpressure field， due to the complex detonation process inside the cylindrical cloud. The pursuit of two peaks resulted in a characteristic mutation phenomenon of small amplitude and small range in the variation curve of the peak overpressure of detonation with scaled distance， and the larger the morphological parameter， the closer the certain position was to the detonation point．Furthermore， when the morphological parameters within the range of 2-4.5， the decay law of the detonation far-field peak overpressure with scaled distance satisfied the same similarity law. The maximum error of the overpressure damage radius obtained based on that similarity law was less than 8%. When the morphological parameters within the range of 0.5-2， the detonation overpressure damage radius decreased with the increase of morphological parameters.