High finesse ultra-stable optical Fabry-Perot (F-P) cavity can provide high-precision frequency standard and fine frequency resolution, it plays an important role in optical frequency atomic clock and quantum precision measurement, and controlling its temperature to the zero-expansion temperature can effectively improve the frequency stability. In the experiment, a set of spherical flat concave F-P cavities made of glass ceramics with ultra-low expansion (ULE) coefficient is designed and prepared. It is plated with 1 560.5 nm and 637 nm antireflection film and placed in an ultra-high vacuum system with accurate temperature control. Using the modulated sideband method, the free spectral range of the ultra-stable optical cavity is 3.145 GHz and the cavity linewidth is ～ 100 kHz. The fineness of the ultra-stable optical cavity in the set wavelength laser can be more than 30 000. On this basis, the 1 560.5 nm laser is doubled to 780.25 nm by the frequency-doubling waveguide device. By comparing the resonant frequency of the ultra-stable optical cavity with the saturated absorption spectra of the rubidium atom, the accurate value of the resonant frequency of the ultra-stable optical cavity at different temperatures is obtained. According to the change of the relative cavity length, the thermal expansion characteristics of the ultra-stable optical cavity system are measured, and the zero expansion temperature is 10.688±0.115?°C. The high finesse optical cavity provides a stable frequency reference, and can effectively narrow the laser linewidth and suppress phase noise. It is an important tool for generating high-quality laser sources. We have applied its excellent short-term frequency stability and extremely low-frequency noise to the 318.6 nm narrow linewidth ultraviolet laser with high stability through 637.2 nm laser cavity-enhanced frequency doubling, and further applied it to the study of cesium atom single-step Rydberg direct excitation and Rydberg dressed ground state cesium atom ensemble.