Preparation method of polyurethane aqueous dispersion and device thereof

The invention discloses a preparation method of polyurethane aqueous dispersion and a device thereof. The preparation method comprises the following steps: polyurethane prepolymer with stabilizer, water and triethylamine solution are respectively sent in a polyurethane emulsifier 4 from the bottom by a metering pump, strong stirring is performed at 50-60 DEG C in 2000-3000rpm, the mixture is sentin a chain-extending kettle from the top of the emulsifier 4, a defined amount of triethylamine solution is added, stirring is performed at the room temperature for 0.5-1h, and the product is placed in a container to be used by the user. The prepared polyurethane aqueous dispersion has the following quality indexes: the particle diameter is 45-75nm, the solid content is 30-42%, the pH value is 7.0-7.5, and the viscosity is 10-30mPa.S at 25 DEG C.