This study proposes a new mixing process for producing commercially acceptable DSP mortar of high flowability, using commercial materials and water-bath curing at about 20°C. That is “three- speed mixing technics (TSMT)”. The properties of mortars mixed by TSMT and conventional technics (CT) are compared. At a water-to-binder ratio of 0.2, the compressive strength of the TSMT mixed DSP mortars was about 41.2% higher than that of the CT mixed DSP mortars of the same composition, the workability was also increased. The increase reason was investigated by the wedge-splitting section and Environmental SEM (ESEM) images. Additionally, for TSMT, the influence of mix-design parameters such as cement grade, the water/binder (w/b) ratio, the silicon fume/cement (sf/c) ration and the superplasticizer/cement (sp/c) ratio were studied.