The method of pectin extraction from sisal residue was optimized by orthogonal experiments, and pectin separation and decoloration were also studied. The optimized extraction conditions were as follows: 2.2 mol·L^-1 oxalic acid-ammonium oxalate buffer as extracting agent, the solid to liquid ratio 0.1 g·mL^-1, time 90 min, temperature 80℃. Pectin was precipitated by alcohol at pH 4.0； the yield of sisal pectin was 14.87%. The primrose yellow pectin was decolored by 1.8%-2.4% H₂O₂. The results of physicochemical property were that the degree of esterification of sisal pectin was 23%, galacturonic acid 66%, pH and ash all complying with Chinese light industey standards.