Abstract: Bamboo leaves were used as raw material, and the composite solvent of petroleum ether and 95% ethanol was used as extraction solvent of chlorophyll.Chlorophyll extracted directly after the step of saponification, acidification, copper replacement, purification, salt formation and so on were prepared as the sodium copper chlorophyllin.There were two key processes, one was the extraction processesaction which affected the product yield and the other was copper replacement processesaction which affected the quality indicators respectively.The process conditions were optimized by L9 (34) orthogonal test.The result showed optimum extraction conditions of the bamboo leaves chlorophyll were 15% of the volume fraction of 95% ethanol in the composite solvent, taking the composite solvent eight times the volume of bamboo leaves as extractant, ratio of liquid to solid 8∶1 (v∶w) , extraction temperature 55℃, extraction time 2h.Best process conditions of copper replacement were the ethanol volume fraction of 85%, the increase of copper content was two times of the theoretical value, reaction temperature 60℃, pH2.5.The product yield of sodium copper chlorophyllin was 0.38%.Main indicators of the test result were in accordance with the national standards of food additives.