The invention discloses a compound desulfurizer. The compound desulfurizer comprises the following components in percentage by weight: 30-40% of N-methyldiethanolamine, 40-50% of steric hindered amine, 10-29% of physical absorption solvent and 0.5-1% of defoaming agent. Meanwhile, the invention further discloses a preparation method of the compound desulfurizer. The compound desulfurizer has the advantages that sulfide in mixed gas can be effectively removed, the selectivity is good, the absorption rate of carbon dioxide is low, the handling capacity of subsequent processes is lowered, the sulfur capacity is high, the foaming is difficult, the use concentration is high, and the circulation volume is low; and meanwhile, no extra desulfurizers are need, the integral energy consumption of a desulfurizing system can be reduced by above 20%.