The invention relates to a construction process for controlling dewatering depth of confined water by combining the automation information system and variable water flow system, which pertains to the field of building engineering. Based on the foundation of detail survey for construction, the invention accurately computes dewatering depth of confined water, adopts the automation information system for collecting the dewatering depth and combines with a variable flow water pumping device, regulates water output amount by monitoring the dewatering depth, and finally reaches confined water dewatering depth control. The invention not only ensures safety of the foundation ditch, but also reduces influence of extracting confined water to surrounding environment by maximum, uses information and networked construction process, automatically alarms, reduces construction cost, reinforces construction management, thus the process is especially suitable for projects in need of confined water but the surrounding with high requirements to environment protection.