The invention discloses a gas flow rate survey meter based on the tunable diode laser absorption spectroscopy technology, comprising a red-light light source, a laser, a signal generator, a laser launcher, a laser receiving device, an optical-fiber interferometer, a data acquisition card, a detector, a locking amplifier and a data processing and displaying module. The gas flow rate survey meter works in an all optical fiber mode, which facilitates the remotely transmission of a signal. Compared with the prior art, the gas flow rate survey meter based on the optical method disclosed by the invention has the advantages of non-invasive monitoring object, high spatial resolution, high dynamic response, high measurement precision and big measurement range. The gas flow rate survey meter is easy to install, prevents dust, prevents from splashing, corroding and shocking and is suitable for monitoring industrial emission with high temperature, high dust content and high toxicity and corrosivity. The gas flow rate survey meter also can be used for measuring high-speed airflow of which the flow velocity reaches thousands of meters / second, and can be used for detecting airplane engines.