In this paper, tetrapod CdS for photodegradation to rhodamine B (RhB) was reported for the first time. Tetrapod CdS was synthesized by one-pot solvothermal method. The category of sulfur source and mixed solvent, the volume ratio of mixed solvent, reaction temperature and time were observed. The synthesized samples were characterized by SEM, XRD, XPS, TEM, absorption spectrum and C-V measurement. The results showed that, tetrapod CdS with wurtzite structure was synthesized successfully with thioacetamide as sulfur source, ethanediamine (EA) and isopropanolamine (IPA) as mixed solvent. Tetrapod CdS was applied in the photo degradation to RhB, it displayed pseudo-first-order kinetics and obtained the maximum photodegradation efficiency up to 99.5%, which may be originated from low electron-hole recombination. Moreover, the photo degradation efficiency and constant rate showed the dependence on the morphologies of tetrapod CdS. Finally, the photodegradation products were characterized by LC-MS to obtain the photodegradation mechanism.