Ultrasonic　testing　is　a　common　non-destructive　testing　technique　for　determining　axial　stress　in　bolted　structures.　The　key　issue　is　the　accuracy　of　the　test　results　needs　to　be　further　improved.　In　order　to　explore　the　influence　factors　of　ultrasonic　wave　on　the　axial　stress　detection　of　bolts,　the　axisymmetric　two-dimensional　finite　element　model　of　bolted　structure　was　established　by　COMSOL　Multiphysics.　The　bolt　is　made　of　a　hyperelastic　material　with　a　third-order　elastic　constant　of　Moanghan　The　ultrasonic　transceiver　is　modeled　and　the　ultrasonic　excitation　signal　is　determined.　Coupling　analysis　of　structure　field　and　sound　field　is　carried　out　to　study　the　influence　of　different　factors　on　ultrasonic　testing　results.　The　results　show　that　the　axial　load　has　a　linear　relationship　with　the　acoustic　wave　propagation　time.　The　greater　the　axial　load　is,　the　longer　the　ultrasonic　echo　takes.　The　acoustic　elasticity　coefficients　are　different　when　the　second　and　third-order　elastic　moduli　that　affect　the　speed　of　sound　are　different　in　the　material,　resulting　in　different　sound　velocities.　Different　bolt　clamping　lengths　correspond　to　different　internal　stress　distribution　states　of　the　bolts,　and　the　corresponding　sound　velocities　are　quite　different.　Under　the　same　load,　the　longer　the　clamping　length,　the　longer　the　ultrasonic　echo　takes.　The　established　model　and　the　analysis　results　have　important　reference　value　for　the　development　and　application　of　the　equipment　of　ultrasonic　testing　bolt　stress.