The invention discloses a cocoon boiling auxiliary agent, and relates to the technical field of textile industry silk making. The cocoon boiling auxiliary agent is prepared by mixing the following rawmaterials in parts by weight: 5 to 10 parts of plant proteinase, 2 to 4 parts of sodium oleate and 0.5 to 0.8 part of anti-foaming agents; the plant proteinase is one or two kinds of materials from papain and ficus proteinase; the enzyme activity of the papain is 1.8 to 2 million U; the enzyme activity of the ficus proteinase is 0.8 to 1.2 million U. The cocoon boiling auxiliary agent solves theproblem of great raw cocoon consumption of the existing cocoon boiling auxiliary agent.