The present disclosure relates to the technical field of loading test devices, relating to a test device for arbitrarily directional combined loading and a method for using the loading test device. The device includes a test bench base assembly and a loading assembly. The loading assembly is arranged above the test bench base assembly. The loading assembly includes a loading oil cylinder and a swing base. The swing base can rotate with respect to the loading base, such that a direction of the loading oil cylinder can be adjusted to meet requirements of different loading angles. The test bench base assembly includes a first chute, and the loading base is connected to the first chute via a sliding fastening bolt.