Patch type liquid level meter and measuring method

The invention discloses a patch type liquid level meter and a measuring method, and relates to the technical field of liquid level meters, the patch type liquid level meter comprises an ultrasonic liquid level meter body and a probe fixing seat, the probe fixing seat comprises an air exhaust cavity, a suction cup and a main sonar range finder are installed in the air exhaust cavity, a piston and an extension spring are slidably arranged in the air exhaust cavity, and symmetrical mounting frames are fixedly arranged on the two sides of the air exhaust cavity; and a rotating frame is arranged on the mounting frame, a propelling bolt is arranged at the bottom of the mounting frame, the top end of the rotating frame is connected with an auxiliary sonar range finder through a balance rotating shaft, and arc-shaped measuring plates are fixedly arranged on the two sides of the air exhaust cavity and located behind the mounting frame. The detection mechanism is tightly attached to the outside of the detected containe