Abstract: The water extraction and preliminary purification technology of tea polysaccharide (TPS) was studied. Main factors of extraction technology such as material-to-liquid ratio, extraction time, extraction temperature, and number of extraction times were researched through single-factor experiments. The optimum extraction technology was confirmed through orthogonal test of L9 (34) . The preliminary purification technologies of alcohol precipitation and deproteintion on tea polysaccharide were investigated. The optimal conditions were as follows:the ratio of material to liquid was 1∶30, extraction temperature was 85℃, extraction time was 2h for three times, ratio of concentrated solution to 95% alcohol was 1∶5, alcohol quiescence time was 6h, and the protein was removed with Sevage method for 3 times. Under these conditions, the final polysaccharide yield was 4.10%.