Exciton properties have a decisive influence in the luminescence mechanism of quasi-2D perovskite material. Measurement of exciton-phonon coupling strength and exciton binding energy is a powerful means of investigating exciton properties of quasi-two-dimensional perovskite materials, which can provide a key scientific basis for revealing the internal light emission mechanism and further improving the fluorescence quantum yield. By combining the adjustable pump intensity fluorescence testing system with the liquid nitrogen thermostat, a set of variable temperature fluorescence test system with adjustable pump intensity is built and controlled by the LABVIEW program. Then the exciton and luminescence properties of quasi two-dimensional perovskite film samples are studied by using the built system. The experimental results show that the exciton-longitudinal optical phonon coupling strength and exciton binding energy decrease with the increase of n-value of quasi-two-dimensional perovskite. In addition, by measuring the adjustable pump intensity fluorescence at room temperature with the built system, the optical gain of quasi-two-dimensional perovskite films is explored, and it is shown that the amplified threshold of spontaneous emission of the film is 3.2 μJ/cm2.