The heavy use of antibiotics has caused great damage to the ecological environment. Photocatalytic technology is widely used in the degradation of pollutants because it is easy to operate and will not harm the environment again. In the process of photocatalytic degradation of antibiotics, the choice of light source is very important for the degradation efficiency of antibiotics. Compared with mercury lamps, which are usually used as photocatalytic light sources, UV-LED have higher energy efficiency and lower energy consumption. Therefore, the application of UV-LED technology has brought about huge changes in the photocatalytic process. First, this paper establishes a photocatalytic platform based on UV-LED array. The spectral characteristics of the LED array light source and the light field distribution in the device are measured and analyzed by a grating spectrometer and an UV illuminometer. The results show that the wavelength of the UV-LED source is between 265 and 295 nm, and its dominant wavelength is 275 nm. Due to the influence of the superposition of the light field, the radial intensity of the device increases significantly with the increase of the radial distance. The distribution of light intensity at the axial position is relatively uniform; Secondly, the particle structure of P25 photocatalyst is characterized by 3D microscope with super wide depth of field and UV-Vis technology. At the same time, the semiconductor derivative formula is used to analyze the band gap of P25. The results showed that the TiO2 was spherical. Due to the excessive relative humidity in the air, the moisture on the surface of TiO2 enhances the adhesion among particles. Therefore, the TiO2 particles have agglomeration. And the band gap of TiO2 is 31 eV. Finally, UV-LED and high pressure mercury lamp are used as the catalytic light source. Photocatalytic degradation of methyl orange (MO) and sulfonamides (SM2) using P25 as a catalyst. Ultraviolet-visible spectrophotometer is used to measure the absorbance in the degradation process, and the degradation rate of antibiotics is further analyzed. The results showed that MO and SM2 could be degraded under UV-LED array. After the catalytic degradation process of 160 and 240 min, the degradation rates reached 70% and 36%. It conformed to the first order kinetic equation. The degradation kinetics constants of MO by LED array light source and mercury lamp were -0007 5 and -0113 5 min-1. The degradation kinetics constants of SM2 were -0001 9 and -0019 4 min-1. Therefore, the degradation rate of the mercury lamp is higher than that of UV-LED array in case of degradation analysis of MO and SM2. In catalytic degradation of pollutants, UV-LED arrays and mercury lamp systems differ in power and in distance from the axis of the reactor, and an evaluation method for the degradation efficiency of antibiotics under two light sources was established. Distance degradation efficiency of UV-LED and mercury lamp at unit power standard was adopted in this paper. For MO, distance degradation efficiency of mercury lamp at unit power is larger than that of ultraviolet LED. For SM2, distance degradation efficiency of the UV-LED array is larger than that of the mercury lamp. Based on the results of various spectral analysis and application above, UV-LED array is a competitive alternative to light source for photocatalytic. The widespread application of this technology provides a new way to degrade antibiotics.