Preparation method of re-tanning type leather inflaming-retarding agent

The invention discloses a preparation method of a re-tanning type leather inflaming-retarding agent. The preparation method of the re-tanning type leather inflaming-retarding agent comprises the following steps of dissolving dimethyl methylphosphate and dimethyl maleate in water, uniformly agitating an obtained first mixture, adding polyvinyl chloride resin and tricresyl phosphate into the agitated first mixture, then adding a re-tanning agent and an emulsifying agent into an obtained second mixture, finally adding acetic anhydride into an obtained third mixture, regulating the pH (potential of Hydrogen) value of a product B to be 3 to 5, and agitating an obtained fourth mixture for 1h to 2h at 80 DEG C to 120 DEG C, so as to obtain colorless and transparent liquid which is the re-tanning type leather inflaming-retarding agent. The re-tanning type leather inflaming-retarding agent has a favorable inflaming-retarding effect; the inflaming-retarding agent cannot be liable to give off a harmful gas in a use proc