Taking Tan-Lu seismic zone as an example, basing on linear least-squares regression theory, we selected the best combination scheme of b-value and V4 in Tan-Lu seismic region from various combination scheme statis- tics of b-value and V4. In addition, we calculated bedrock horizontal peak acceleration of each combination scheme under different probability of exceedance by probability seismic hazard analysis method, and discussed the influence degree and law of uncertainty of seismic activity parameter b-value and V4 On seismic risk analyze result. The statistical analysis of b-value and I/4 and its uncertainty could be used as the reference of seismic ac- tivity and risk evaluation researches and had important significance for seismic zoning, and seismic safety assess- ment of engineering site.