Excessive solar UV radiation can cause erythema on human skin and even skin cancers in severe cases. In this paper, we study the solar erythemal UV radiation and UV spectra in the Mount Everest region (Tingri), Lhasa, and Nyingchi of Tibet by using a NILU-UV irradiance meter and a RAMSES-ACC-UV spectrometer during the period from January 2014 to December 2018. In addition, we observe the characteristics of solar UV spectra in Lhasa at local noon near the vernal equinox and autumnal equinox and at the winter solstice and summer solstice. We figure out that almost all the solar UV radiation with wavelength less than 300 nm is absorbed by the atmosphere and can not reach the surface of Tibet. Based on the analysis of solar erythemal UV radiation doses on clear days measured in Tibet, we find that only UVB causes the human skin erythema. Moreover, the field observation data show that the dose rate of solar erythemal UV radiation on clear days in Tibet changes in a typical parabola shape with the time of the day. Moreover, the average occurrence time of the maximum dose rate is about 10 min around the local noon as the solar altitude angle increases. In theory, the solar erythemal UV radiation intensity on clear days rises day by day from the winter solstice and reaches the highest value at or near the summer solstice in Tibet. However, in fact, the peak intensity on clear days during the observation period generally appears at the end of March due to few clear days in the summer of Tibet. The research results disclose that the maximum dose rates of solar erythemal UV radiation on clear days in the Mount Everest region (Tingri), Lhasa, and Nyingchi during the observation period from the winter solstice to the summer solstice are 113.40--343.10 mW·m ^-2, 85.26--344.2 mW·m ^-2, and 62.78--197.10 mW·m ^-2, respectively, in contrast, the total maximum daily doses reach 7181.00 J·m ^-2, 7623.00 J·m ^-2, and 3994.00 J·m ^-2, respectively. These indicate that skin erythema is easily induced in Lhasa and the Mount Everest region (Tingri).