This paper starts from the behavior of the field in a potential well and concludes that the field exists in the form of a standing wave with energy in the potential well, thereby finding the cause of the fluctuation in quantum mechanics. Using only one physical model, the field forms fluctuations, which is the wave function, and using the Compton wavelength, the relationship between electromagnetic wave energy and mechanical wave energy and frequency is derived. It is concluded that the wave function has the meaning of a generalized field, and it is noted that Sommerfeld's quantization rule is the basic equation of quantum mechanics, thus establishing a new quantum mechanics theory. The superposition, orthogonality, normalization, and equivalence principles of the wave function are analyzed, and the superposition of wave function states does not exist. Each conclusion given herein has a clear and obvious physical meaning, making the problem of quantum mechanics simple and clear. A new atomic model is established, There is a closed annular electromagnetic wave at the energy level outside the nucleus, and problems such as electron transitions, electron spin, electron emission and absorption are discussed. Matter is divided into solid matter and field-state matter. The essence of light is particularly analyzed, and it is clear that light is an electromagnetic wave and that light is not a material particle. Experiments such as the electron pattern of the Davissonu2012Germer experiment, the principles of electron microscopy, the photoelectric effect, the Compton effect, and double-slit interference are reinterpreted. A new uncertainty relation is proposed. Notably, there is no wave, no "waveu2012particle duality", no quantum entanglement, and the Schrödinger equation is not a wave equation.