put 320 kg of octylphenol and 150 kg of formaldehyde (30% aqueous solution) into the reaction kettle, add catalyst sodium hydroxide, raise the temperature to 80 ℃ within 30 min under stirring, keep the temperature at 80~85 ℃ for 1 h, and sample and analyze the formaldehyde content <0.10% reaction is completed. Then cool to 40 ℃ and vacuum dehydrate. The temperature is raised to 150 ℃ within 1 h, the air in the kettle is replaced with nitrogen after dehydration is completed, and 700 kg of ethylene oxide is started after the air is cleared. The reaction temperature is controlled at 160~180 ℃ and the pressure is 0.2~0.3 MPa. After the reaction, the temperature was lowered, and the pH value was 5.0~7.0 with acetic acid. Then put the package into the finished product.