Abstract: For buried steel pipelines affected by dynamic DC interference, sufficient cathodic protection potential data are often unavailable for routine risk assessments. This study evaluates and compares the dynamic stray current corrosion risks of pipelines using two separate datasets: sampled potential data and population potential data that meet standard requirements. Through mathematical derivation, a recommended minimum sample size and an appropriate sampling interval are proposed for cathodic protection potential under specific acceptable error limits (α₀ = 15%, β₀ = 10%, γ₀ = 15%). To verify the validity of the proposed method, the scheme recommended is compared with the data volume and assessment criteria specified in Standard SY/T 0087.4. Corrosion risk assessment is carried out using measured data from 72 typical measuring points. The results indicate that the error between the assessment results based on sampled data and those obtained by the standard method falls within the acceptable range. The research conclusions enable rapid identification of pipeline corrosion risk when potential data are insufficient under dynamic DC interference. They also provide a theoretical basis for configuring sampling intervals of intelligent test posts.