The invention discloses a water turbine parameter identification method based on self-adaptive chaotic and differential evolution particle swarm optimization. The water turbine parameter identification method is characterized by comprising the following steps of firstly, determining a nonlinear mode of a water turbine; secondly, acquiring frequency step test data; thirdly, determining a fitness function of the self-adaptive chaotic and differential evolution particle swarm optimization; fourthly, setting a basic parameter of an identification algorithm; fifthly, calculating a fitness function value of particles and an individual extreme value of the particles in a swarm as well as a global extreme value of the swarm and updating the speed and the position of the particles; sixthly, carrying out premature judgment, if the premature is judged, carrying out differential mutation, transposition, selection and other operations to avoid local optimization; seventhly, checking whether the algorithm meets end conditions or not, if so, outputting an optimal solution, and otherwise, self-adaptively changing an inertia factor and executing the fifth step to the seventh step again. According to the water turbine parameter identification method disclosed by the invention, a water hammer time constant of the water turbine is identified, and the algorithm is high in convergence speed and convergence precision; in addition, test data of the water turbine at any load level can be utilized, so that the test cost is effectively reduced.