The static and dynamic load tests and numerical analysis were carried out on an existing threespan (65m+  85m+65m) half-through arch bridge with suspension deck system. In which, the deflection and strain of arch rib, bridge deck, cross beam and suspender under static load were measured, the check coefficient was analyzed, the impact coefficient and suspender tension were tested, and the natural vibration characteristics were analyzed. Results show that the certain arch foot stiffness against negative bending moments is poor under static load, while the strength and stiffness of other components meet the specification requirements. The error of suspender tension between the measured and calculated values under dynamic load is less than 15%, and the strength meets the requirements of specifications, but the measured impact coefficient is bigger. The natural vibration characteristic mode analysis indicates that the free vertical bending vibration frequency is close to the free torsional vibration frequency. Moreover, there may be a vehicle-bridge resonance on the side span of bridge. The vibration characteristics of vehicle-bridge coupling are poor which is harmful for the fatigue stress of booms, especially the short booms.