Abstract: A intelligent lighting system based on Siemens S7-1500 PLC control architecture was designed to address mismatch between lighting environment management of large-scale dairy farms in Yunnan Province and physiological needs of cows, which affected their lactation performance．An optimization method was explored for regulating parameters that meet actual lighting needs of cows, aiming to improve lighting environment of cowshed, enhance health, production welfare, and production performance of cows．It was hoped to provide reference for improving lighting environment of cowsheds in other large-scale dairy farms．