In ladder type EIT, decreasing probe optical power and increasing coupling beam power can minimize the population of the middle state in vapor cell. This is essential for the lifetime of coherent state between Rydberg atom and ground state. Due to the broadening of the atomic spectral by increasing probe power, we set the probe power below the saturated intensity. In comparison, the EIT peak increases as the coupling laser power increases; however, the spectrum linewidth is only broadened slightly. For a high electric-field strength, we should increase the coupling laser power to distinguish AT splitting peaks. We have developed strong engineering applicability and high stability Rydberg atomic excitation light system based on CEDL. The laser linewidth is about tens of kHz, with a flexible wavelength tuning, providing fast and slow feedback channels for locking center frequency. The 1018 nm CEDL is the ideal seed laser for YDFA. Based on the fiber-coupled single-pass crystal frequency doubling, the power of the single-frequency narrow line width of 509 nm laser is about 470 mW. Meanwhile, its power and the linewidth parameter can meet the Cs atomic Rydberg atom EIT spectrum applications. The preparation and optimization of EIT signal measurement is the next step in building a reliable microwave field strength measurement system based on the above laser system.