An arbitrary order Bessel beam with arbitrary incidence is generated numerically in finite-difference time-domain (FDTD) method using a total-field/scattered-field (TF/SF) approach. This is implemented by decomposition of Bessel beam into a series of plane waves, which are projected into the FDTD simulation domain. The off-axis incidence case is realized by tuning the arrival time when the elementary plane wave gets to the center area of simulation domain, and the oblique incidence case is implemented by rotating the plane waves through Euler angles. Numerical examples concerning backscattering radar cross-sections (RCS) are presented to demonstrate the validity, accuracy, and capability of the proposed method. The results in this paper provide an efficient way to investigate the interactions of Bessel beams and particles with complex shape and composition using FDTD.