We report the confirmation of a sub-Saturn-size exoplanet, TOI-1194 b, with a mass of about ${0.456}_{-0.051}^{+0.055}$ M J, and a very low mass companion star with a mass of about 96.5 ± 1.5 M J, TOI-1251 B. Exoplanet candidates provided by the Transiting Exoplanet Survey Satellite (TESS) are suitable for further follow-up observations by ground-based telescopes with small and medium apertures. The analysis is performed based on data from several telescopes worldwide, including telescopes in the Sino-German multiband photometric campaign, which aimed at confirming TESS Objects of Interest (TOIs) using ground-based small-aperture and medium-aperture telescopes, especially for long-period targets. TOI-1194 b is confirmed based on the consistent periodic transit depths from the multiband photometric data. We measure an orbital period of 2.310644 ± 0.000001 days, the radius is ${0.767}_{-0.041}^{+0.045}$ R J and the amplitude of the RV curve is ${69.4}_{-7.3}^{+7.9}$ m s‑1. TOI-1251 B is confirmed based on the multiband photometric and high-resolution spectroscopic data, whose orbital period is ${5.963054}_{-0.000001}^{+0.000002}$ days, radius is ${0.947}_{-0.033}^{+0.035}$ R J and amplitude of the RV curve is ${9849}_{-40}^{+42}$ m s‑1.