Abstract: According to the technical requirements of cold-rolled high strength low alloy steel HC340LA for automobile,the alloy system design of the steel was carried out. The recrystallization temperature experiment was carried out in the laboratory. According to the experimental results, the industrial production program was established, and the continuous annealing process was studied in the production site. The microstructure analysis and mechanical properties testing of the products produced in industrial production were carried out, and the best annealing process for automotive cold rolled low alloy high strength steel HC340LA products was determined. The results show that the annealing recrystallization temperature of the steel is 675℃, and the industrial production anneling temperature is 780℃.