The invention relates to a fuel assembly and a fuel rod capable of improving reactor security of the fuel assembly. The fuel assembly comprises an integrated fuel rod body containing a nuclear fuel component; an axial perforative through hole is formed in the middle part of the fuel rod body. The through hole of the fuel rod provided by the invention can remarkably add the heat transfer area, reduce heat flux within a unit area of the fuel rod under the condition of constant reactor capability, and lower the probability of generating departure nucleate boiling; meanwhile the temperature of the center area of the fuel rod can be greatly lowered, thus the safety margin of the fuel rod under normal condition and accident condition of the reactor is greatly increased.