Synthesis process for nylon 614

The invention relates to a synthesis process of nylon 614 and belongs to the field of chemistry and chemical engineering. The synthesis process is characterized in that hexanediamine and tetradecenoic acid are added into a solvent, stirred for a reaction, and cooled to obtain a salt after the pH value is 6.5-8.0, the salt solution is centrifuged, and then the centrifuged salt or a mixture of the salt and a polymeric additive is added into a polymerization kettle; or hexanediamine and tetradecenoic acid or hexanediamine, tetradecenoic acid and the polymeric additive are added into the polymerization kettle directly; the temperature is raised to 180-300 DEG C, then a reaction is carried out at the pressure of 0.1-3.0MPa for 2-8 hours; then the pressure is reduced to 0Mpa to -0.05MPa in 0.5-4 hours and the reaction is continued for 0.5-4 hours; the final product is obtained after processes of discharging, cooling and granulating. The produced product can replace nylon 11, nylon12 and nylon 612 in various aspects