Flotation equipment is an important gas–liquid reaction device in the field of mineral processing engineering. Flotation equipment has been used for one hundred years. With the rapid development of society, flotation equipment has gradually developed towards automation and large-scale. In recent years, more and more researches and analysis of hydrodynamic characteristic parameters in flotation equipment have been carried out, which has further promoted the reasonable enlargement and optimization of equipment. This work briefly introduced the current development and application status of flotation equipment, then summarized in detail the detection methods, principles and the current research status of three important hydrodynamics characteristic parameters in flotation equipment: bubble size, gas holdup and bubble velocity. According to the current development direction of mineral processing equipment, it was pointed out that how to accurately detect the parameters of the flotation bubble and improved the adaptability of the detection device, and widely applied in the industry to improve the flotation index are still a key issue that researchers faced at present. Image processing technology which can detect multiple characteristic parameters in the flotation equipment had been widely used, but bubble image processing methods which the majority of research scholars had put forward at present have limitations, and failed to involve many complicated details and the actual environment of concentrator, leading to the poor stability and low accuracy of bubbles when bubbles feature was extracted. Therefore, it was necessary to develop machine vision technology that was used in a variety of complex environments and had a strong ability to sort complex problems. At the same time, some sophisticated intrusion detection equipment such as conductivity probes still had certain defects in complex flotation environments. How to design and develop intrusive devices that are more conducive to complex flotation environments was one of the current research direction.