||The accurate design of the sprinkler system is very important for a rack-type warehouse because it has high fire loads and it is very difficult to suppress the fire due to the high loads. In this study, the hydraulic calculation using the PIPENET program was performed and the results were compared and analyzed to investigate the optimal design method according to the piping design methods for the automatic rack-type warehouse. The design methods are about the design of the pipe schedule system based on the fire safety standard, the design for the efficient construction, and the design using the upper limit value of piping. The design of the pipe schedule system, which adopts a predetermined piping size according to the number of heads, is easy to design, but there is a concern that the quantity of water is increased and the water source is soon exhausted. The design for the efficient construction, which has the diameter of the end portion is largely applied to improve the construction efficiency, increases the construction cost slightly but the required amount of water is decreased. The design using the upper limit value of piping, which limits the maximum size of piping to be less than a certain value, can save the construction cost as well as the quantity of water, so it improves safety and reliability of the sprinkler system.