The utility model provides a fungus sack opening making machine automatic control system and belongs to a fungus production device. An electric power main line connects a foot-operated power switch with a power supply. Electric power branch lines connect the foot-operated power switch with time delay relays A, B and C. Three electric power branch lines connect the time delay relays A, B and C with two-position three-way solenoid valves A, B and C in order. Three circular air transmission soft branch pipes A, B and C connect the two-position three-way solenoid valves A, B and C with bidirectional air cylinders A, B and C in order. The air cylinder rod A of the bidirectional air cylinder A is connected with the lower connection rod of the fungus sack opening making machine. The air cylinder rod B of the bidirectional air cylinder B is connected with the pallet of the fungus sack opening making machine through engagement of a rack and a gear. The air cylinder rod C of the bidirectional air cylinder C is connected with the insertion rod of the fungus sack opening making machine. Four-way air transmission soft pipes connect an air pump with the two-position three-way solenoid valves A, B and C. The system is simple in structure, the manufacturing cost is low, operation is reliable, the automation degree is high, and the operation, adjustment and maintenance technology difficulty is low.