The invention provides preparation of biodiesel raw material and an alcoholization-transesterification method. Chinese indigenous oil round tree species are developed and utilized, which are planted on a large scale on rocky desertification waste mountains, waste slopes or idle land in limestone areas of eight provinces/regions near the tropic of cancer in China and have great prospective capacity and reserves, and harvests seeds and fruits of oil round trees to press oil used as raw material for preparing biodiesel. A black-gauze net-bag plant protection technique and extensive management are adopted, so that the biodiesel raw material is suitable for industrial development; and a novel process comprising pipeline reflux-type quicklime catalysis, heating, pressurization, turbulent flow and charged sealing alcoholization-transesterification is adopted. The invention has the advantages of improving processing efficiency of preparation, reducing the pollution of 'Three wastes' emission, developing a closed reflux-type preparation process free from grain oil and raw material supply source and showing an environment-friendly ecological industrial pattern.