The present disclosure provides a control method of a fluid device. The control method includes the steps of (a) providing the fluid device, which includes a plurality of flow guiding units manufactured by a micro-electro-mechanical-system process; (b) dividing the flow guiding units into a plurality of groups, which are electrically connected to and controlled by a control module; and (c) generating a driving signal by the control module for a corresponding one of the groups, wherein the control module generates a high level signal to a specific one of the groups, so that the flow guiding units of the specific one of the groups are driven to transport fluid, and thereby controlling the fluid device to discharge a specific amount of fluid.