The invention provides a technology for synthesizing acetic acid. A production technology mainly comprises the following step: enabling CO and methanol to generate the acetic acid in a reaction kettleunder the conditions that the pressure is 2.3 to 3.5Mpa and the temperature is 180 to 200 DEG C and under the actions of a rhodium catalyst, an iodomethane accelerant and a lithium iodide stabilizingagent; meanwhile, uniformly recycling an iodine-containing substance in a production process; after oxidizing the iodine-containing substance to obtain the acetic acid, recycling, wherein the recycled catalyst and extraction agent can be repeatedly utilized. A whole process technology is advanced and has the advantages of sufficient energy utilization, less energy source consumption, low production cost, high production efficiency and less investment equipment; a zero-emission environment-friendly technology is realized.