The invention relates to a light-based flow counting device including a video colleting circuit, a control circuit, a video processing circuit, a flow counting circuit, a storage and recording circuit and a power source. The control circuit feeds control commands to the video collecting circuit according to current dynamic video signals for self-adaptive parameter adjustment. The video processing circuit performs corresponding processing on input standard dynamic video signals and then sends dynamic video signals only containing vehicle light information to the flow counting circuit. The flow counting circuit performing counting on vehicle lamps in a current view field and calculates dynamic vehicle flow information in real time and outputs the information to the storage and recording circuit for storing and recording. According to the invention, vehicle lamp signals are highlighted through filtering a background in the view field. The counting accuracy and reliability are improved by removing background interference and enhancing the valid signals. The environment adapting capability of the device is enhanced. The device provided by the invention can act as an expansion module and be applied to a current flow counting device and can also work as a separate system working independently or as a portable device applied to a vehicle or a place requiring short term quick mounting.