Using benzaldehyde, N-benzyl-N-ethyl-m-toluidine (N-benzyl-N-ethyl-m-toluidine) and p-aminophenethyl ether as raw materials, benzaldehyde and N-benzyl-N-ethyl ether are used as raw materials. base m-toluidine condensation, and then the condensation product is sulfonated to obtain trisulfonic acid compound, which is then oxidized, reacted with p-aminophenethyl ether, and neutralized to obtain the product. 1000kg of N-ethyl-N-benzyl-m-toluidine was added to the mixed solution consisting of 214kg of 100% sulfuric acid, 126kg of ice and 14kg of ethanol, then 245kg of benzaldehyde was added, reacted at 100°C for 50h, and heated to 110°C within 10h Part of the water was evaporated, and then the material was quickly poured into the tray, and a large amount of water evaporated to obtain about 1500kg of condensate. 750kg of condensate was added to 1500kg of 100% sulfuric acid within 24h until it was completely dissolved, 1040kg of 65% oleum was added dropwise at below 30°C, and stirred until the reaction was complete. Then poured into 3000L of water and 1500kg of ice, heated to 80°C, and then added 2700kg of sodium sulfate to separate out the sulfonated product and filtered. After diluting 1/4 of the sulfonated product with water, add 20kg of 50% acetic acid and 30kg of 30% hydrochloric acid, heat to 45°C, then add 96kg of 100% lead peroxide (to make a paste with 200L of water), and after reacting for 30min, add 80kg of sulfuric acid Sodium, precipitated lead salts, filtered at 45 ℃. The filtrate was salted out with 20% brine (by volume), filtered, and the filter cake was washed with 20% brine and dried under vacuum at 95°C to obtain the oxidized product. Take 600kg of oxidation product, add it to 750kg of p-ethoxyaniline at room temperature, heat to 100-105℃, react for 3.5h, cool down to 60-70℃, add 5000L water and 800kg 30% hydrochloric acid mixture, stir for 1h, siphon Remove the p-ethoxyaniline mother liquor, add 2000L of hot water, stir for 30min, and after standing, siphon off the p-ethoxyaniline washing water. The viscous dye was dissolved in the hot water of 35kg of sodium chloride and 30kg of sodium acetate, then about 80kg of acetic acid was added to make it acidic, the dye was separated out, the waste water was siphoned off, and vacuum-dried to obtain about 500kg of the dye.