This application discloses a fluid measuring method and device and electronic equipment. When a fluid flows in a target pipeline, high-speed cameras obtain a first sampling image set of a tracer particle cluster in the fluid passing a front end of the target pipeline and a second sampling image set of the tracer particle cluster passing a rear end of the target pipeline, thereby obtaining passing time distribution information of the tracer particle cluster passing through the target pipeline. A mean residence time of the fluid in the high-pressure target pipeline is obtained based on the passing time distribution information. In this way, the accuracy of non-intrusive online measurement of the mean residence time of the supercritical pressure fluid in the pipeline is improved.