Using a portable microcomputer multi-channel gamma spectrometer to directly measure the radioactive content in the soil, the on-site gamma energy spectrum measurement was carried out on the soil of 7 parks in a certain city. The survey results show that the specific activity of 40k in the urban park soil ranges from 470.88 bq/kg to 640.2 bq/kg. The specific activity of 238u ranges from 26.77 bq/kg to 33.31 bq/kg. The specific activity of 232th ranges from 42.14 bq/kg to 54.72 bq/kg. The content of the three radionuclides in the soil in the park is lower than the national average, and far lower than the radioactivity of ordinary building materials.