A micro detecting device includes a flying main body, at least one fluid actuation system, an image capture system and a controller. The fluid actuation system is disposed within the flying main body and includes a driving module, a flow guiding channel, a convergence chamber, plural valves and a fluid discharging zone. The driving module is consisting of plural flow guiding units for transporting fluid. The flow guiding channel includes plural diverge channels which are in fluid communication with plural connection channels. The convergence chamber is in fluid communication between the corresponding diverge channels. The valves are respectively disposed in the corresponding connection channels and controlled in open/closed state for the corresponding connection channels. The fluid discharging zone is in communication with the connection channels. The image capture system is used to capture external image. The controller is connected to the valves to control the valves in the open/closed state.