Plateau lakes have significant ecological value. With economic development, lake pollution and ecological degradation have become increasingly prominent. There are many ecological risk assessment methods. This article combines four different ecological risk assessment methods including single-factor pollution index, geological accumulation index method, potential risk index method, and pollution load index method to analyze the heavy metal pollution in Yangzong seabed mud as comprehensively as possible. It shows that the results obtained by different ecological risk assessment methods are slightly different. The overall trends of the geological pollution index and the single-factor pollution index are similar. In terms of time, except for the two elements of mercury and cadmium, the contents of other heavy metals in 2019 are lower than in 2018, indicating that heavy metal pollution has decreased in 2019; from the perspective of spatial distribution, In 2018, the overall pollution level on the south side of Yangzonghai was higher than that in the central and northern regions of Yangzonghai . On the whole, whether it is the potential risk index or the appropriate pollution load index, the pollution level on the south side of Yangzonghai is higher than that in the central and northern areas of Yangzonghai, and the northern area has the least pollution.