The invention provides a greenhouse environment regulation method and a greenhouse environment regulation device. The method comprises the following steps of: acquiring a current optical radiation value of a greenhouse environment in real time; sending a control signal to shielding equipment to shield light when the current optical radiation value is more than a preset threshold value, and acquiring a to-be-regulated temperature range according to a first relationship table when the optical radiation value is less than or equal to the preset threshold value, acquiring a to-be-regulated humidity range according to the to-be-regulated temperature range, and acquiring a to-be-regulated carbon dioxide fertilization range according to the second relationship table; calculating all-day radiation cumulant according to the current optical radiation value and daily preset radiation cycle, and determining a to-be-supplemented time according to the all-day radiation cumulant, a preset all-day radiation cumulant and unit time radiation value of light supplement equipment; determining whether the current optical radiation value is equal to a preset historical average daily radiation amount or not, and determining a to-be-regulated water quality according to the determination result; and regulating the greenhouse environment according to the to-be-regulated values. According to the method and the device, each parameter is regulated online by taking the optical radiation value as driving, the coupling influence is simplified, the photosynthesis effect is improved, and the respiration effect is reduced.