The　movement　of　the　crust　results　in　the　structural　stress　in　the　rocks　up　to　its　rupture　strength,　rupture-delay　strength　or　friction　strength.　The　existence　and　increase　of　structural　stress　are　the　main　reason　of　earthquake　and　geological　disaster.　So　the　calculation　and　result　analysis　of　structural　stress　field　is　very　important　in　deducing　and　predicting　of　dangerous　disaster　zones,　engineering　evaluation　of　geological　condition,　and　appropriate　analysis　of　city＇s　site.　Based　on　elastic　mechanics　and　finite　element　method,　structural　stress　field　of　Tangshan　city　is　calculated　and　analyzed.　According　to　the　results　of　stress　field,　the　distribution　of　underground　fracture　is　analyzed.　Moreover,　the　prediction　model　for　disaster　risk　evaluation　is　constructed　by　the　method　of　artificial　neural　network.　As　an　example,　both　the　results　of　underground　environment　analysis　and　the　predictive　model　are　applied　to　evaluate　the　distribution　of　earthquake　affecting　coefficient　in　Tangshan　city.　Finally,　the　city　planning,　disaster　prevention　and　mitigation　of　Tangshan　city　are　discussed　through　the　analysis　of　predictive　results.　Some　conclusions　and　suggestions　for　city　construction　and　planning　are　given.