Abstract: Provided is an active ultrasonic flow meter. The flow meter includes a flow rate measurement sensor for measuring a flow rate in a pipe by an ultrasonic method; a data collection unit for collecting environmental data according to temperatures of the pipe and fluid, a state of the fluid, a state of the pipe, and an external environment of an ultrasonic sensor; a diagnosis module for being learned through deep learning based on a flow rate measurement value of the flow rate measurement sensor and the environmental data, analyzing the current flow rate measurement value input, and outputting the analyzed flow rate measurement value and diagnostic data on normal and abnormal states of the flow rate measurement; and a controller for receiving data output from the diagnosis module, displaying the flow rate measurement value and the diagnostic data, transmitting the value and data to a server, and generating an alarm.