The finite element method(FEM) was realized by Matlab program.Bio-heat transfer model is classical Pennes equation with blood perfusion term,the liver tissue temperature response at flat laser beam from Nd:YAG laser was researched.Under the cylinder coordinate three dimension temperature distribution was reduced to axial and radial two dimension.The three dimensions color figure animation display was possible.The results showed the blood perfusion can avoid local high temperature and make the temperature rise to a stable state in a short time.Under this stable temperature,the cure effect can be enhanced and the cure time can be shortened.The photo and thermal parameters of tissue can affect the model results,the computation precision and time should be considered compromisingly.