Taking the automatic production line of plant fiber molding products as the research object，the technological process and technological requirements of the production line were analyzed, an optimized hydraulic system design scheme was put forward.The hydraulic system circuit of the automatic production line was designed, and the technical parameters of hydraulic components were calculated and the assembly test was carried out.Compared with pneumatic split production equipment,the designed hydraulic automatic production line can increase the production efficiency of a single product by about 25% and the daily production by about 50%.Therefore, the design of hydraulic automatic production line is reasonable,it can meet the process requirements and operate reliably and stably, and it has good economic and social benefits.