The mechanism of hydraulic cavitation is far from known for the complexity of itself. The core of the technology of hydraulic cavitation is the cavitation nozzle. Researches show that cavitation phenomenon displays some chaotic properties. On this basis，the cavitation noise signals，which are produced by the common cavitation nozzles in different shape，are collected by hydrophone experimentally. The state spaces of some selected signals are built on the base of taken theorem，and their largest Lyapunov exponents are calculated. This experiment identifies and compares the chaotic properties of cavitation nozzle，and presented a new method for the design and the test of cavitation nozzles. Under this experimental condition，the result displays that the largest Lyapunov exponents of these selected cavitation noise signals are larger than 0，which means that these signals are all chaotic signals. The largest Lyapunov exponent of the nozzle with self-oscillating cavity is the largest of the three.