The invention discloses an environmental-condition-controllable laboratory simulation experiment device for CO2 flux in an intertidal zone. The laboratory simulation experiment device comprises a biochemical incubator, an outer barrel and a water stooge tank, wherein the outer barrel is located in the biochemical incubator, an inner barrel is arranged in the outer barrel, sediment samples acquired in field are placed into the inner barrel in a layered manner, permeation holes are formed in the bottom of the inner barrel, water through holes are formed in the inner barrel and located above the sediment samples, the outer barrel is connected with the water storage tank through a peristaltic pump, a sampling gas chamber is formed above the sediment samples in the inner barrel and connected with a CO2 sensor through a gas channel pipe, and the CO2 sensor is in signal connection with a computer. The environmental-condition-controllable laboratory simulation experiment device for CO2 flux in the intertidal zone can simulate various temperatures, light environment conditions and underground water level in a laboratory, CO2 flux in intertidal zone sediments is observed continuously for a long time, and powerful observation and research means are provided for fundamental research of carbon metabolism, carbon cycle and the like of a wetland ecosystem.